Anatomy of the Heart: Pericardium and Endocardium
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Anatomy of the Heart: Pericardium and Endocardium

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Questions and Answers

What type of tissue is the fibrous pericardium composed of?

  • Simple squamous epithelium
  • Dense fibrous irregular connective tissue (correct)
  • Smooth muscle tissue
  • Cartilaginous tissue

    • Which function is NOT attributed to the fibrous pericardium?

  • Prevents the heart from overfilling with blood
  • Protects the heart from trauma and damage
  • Anchors the heart to surrounding structures
  • Facilitates blood flow to the heart (correct)

    • What is covered by the endocardial lining?

  • Pulmonary veins
  • Mitral valve and aortic semilunar valve (correct)
  • Coronary arteries
  • Epicardial surface

    • In which part of the heart is the endocardial lining present?

    <p>In all chambers of the heart</p> Signup and view all the answers

    Which of the following helps to prevent the heart from overfilling with blood?

    <p>Fibrous pericardium</p> Signup and view all the answers

    What is one primary role of the fibrous pericardium?

    <p>It anchors the heart to surrounding structures.</p> Signup and view all the answers

    How does the fibrous pericardium contribute to heart function?

    <p>By anchoring the heart and preventing overfilling.</p> Signup and view all the answers

    What type of tissue is the endocardium primarily composed of?

    <p>Simple squamous epithelium</p> Signup and view all the answers

    Which structure does the endocardium cover?

    <p>The heart chambers</p> Signup and view all the answers

    What is a characteristic function of the fibrous pericardium in relation to trauma?

    <p>It acts as a barrier to prevent trauma to the heart.</p> Signup and view all the answers

    What is the primary function of the tricuspid valve?

    <p>To allow blood flow from the right atrium to the right ventricle</p> Signup and view all the answers

    Which structures are involved in preventing backflow of blood in the heart?

    <p>Chordae tendineae and valves</p> Signup and view all the answers

    Which chamber of the heart receives blood from the pulmonary veins?

    <p>Left atrium</p> Signup and view all the answers

    Which layer of the heart is primarily responsible for the contractile function?

    <p>Myocardium</p> Signup and view all the answers

    What is the location of the apex of the heart?

    <p>Towards the left hip</p> Signup and view all the answers

    Which valve prevents blood from flowing back into the right ventricle after it has exited to the lungs?

    <p>Pulmonary semilunar valve</p> Signup and view all the answers

    What separates the right atrium from the right ventricle?

    <p>Tricuspid valve</p> Signup and view all the answers

    What is the primary role of the interventricular septum?

    <p>To separate the right and left ventricles</p> Signup and view all the answers

    Which of the following vessels arises from the left ventricle?

    <p>Aorta</p> Signup and view all the answers

    What is the approximate weight range of the human heart?

    <p>200-300 grams</p> Signup and view all the answers

    What distinguishes the left ventricle from the right ventricle in terms of its myocardial thickness?

    <p>The left ventricle has a thicker myocardium.</p> Signup and view all the answers

    Which layer of the heart forms the outer surface known as the epicardium?

    <p>Visceral layer of the serous pericardium</p> Signup and view all the answers

    What is the primary function of the pericardial cavity?

    <p>Cushions the heart and reduces friction.</p> Signup and view all the answers

    Which statement about the parietal layer of the serous pericardium is accurate?

    <p>It lines the interior of the fibrous pericardium.</p> Signup and view all the answers

    What is NOT a function of the fibrous pericardium?

    <p>Providing a layer of muscle for heart contractions.</p> Signup and view all the answers

    How does the fibrous pericardium prevent heart overfilling?

    <p>By its non-distensible nature.</p> Signup and view all the answers

    Which valves are covered by the endocardium?

    <p>Mitral (bicuspid) and aortic semilunar valves.</p> Signup and view all the answers

    What characteristic does the fibrous pericardium provide in relation to the heart?

    <p>A tough outer sac that provides protection.</p> Signup and view all the answers

    What type of connective tissue predominates in the fibrous pericardium?

    <p>Dense fibrous irregular connective tissue</p> Signup and view all the answers

    Which structure is primarily involved in cushioning the heart?

    <p>Pericardial fluid</p> Signup and view all the answers

    What distinguishes the left ventricle from the right ventricle?

    <p>The left ventricle has a thicker myocardium.</p> Signup and view all the answers

    Which valve is located between the right atrium and the right ventricle?

    <p>Tricuspid valve</p> Signup and view all the answers

    Which of the following accurately describes the location of the apex of the heart?

    <p>Pointing towards the left hip.</p> Signup and view all the answers

    Identify the primary pacemaker of the heart.

    <p>SA node</p> Signup and view all the answers

    What is the primary role of the pericardial cavity?

    <p>To cushion and protect the heart.</p> Signup and view all the answers

    Which chamber of the heart receives deoxygenated blood from the superior vena cava?

    <p>Right atrium</p> Signup and view all the answers

    Which layer of the heart is responsible for its contractile function?

    <p>Myocardium</p> Signup and view all the answers

    Which valvular structure prevents backflow of blood from the aorta into the left ventricle?

    <p>Aortic semilunar valve</p> Signup and view all the answers

    Which structure drains blood from the heart itself into the right atrium?

    <p>Coronary sinus</p> Signup and view all the answers

    What is the approximate weight range of the human heart?

    <p>200-300 grams</p> Signup and view all the answers

    What structure serves to separate the right and left atria in the heart?

    <p>Fossa Ovalis</p> Signup and view all the answers

    Which of the following arteries is NOT a branch off the aortic arch?

    <p>Right Pulmonary Artery</p> Signup and view all the answers

    What role do the chordae tendineae play in the heart?

    <p>Anchor valves and prevent prolapse</p> Signup and view all the answers

    Which vessel carries deoxygenated blood from the right ventricle to the lungs?

    <p>Pulmonary Trunk</p> Signup and view all the answers

    What is the primary function of the papillary muscles in the heart?

    <p>To attach to the atrioventricular valves</p> Signup and view all the answers

    What is a primary characteristic of the fibrous pericardium?

    <p>It provides a protective and anchoring role.</p> Signup and view all the answers

    Which of the following structures helps to separate the right ventricle from the right atrium?

    <p>Tricuspid Valve</p> Signup and view all the answers

    Which feature of the fibrous pericardium contributes to preventing the heart from overfilling with blood?

    <p>Its non-distensible nature</p> Signup and view all the answers

    Which artery branches off the brachiocephalic artery?

    <p>Right Common Carotid Artery</p> Signup and view all the answers

    What is the function of the interventricular septum?

    <p>To prevent blood mixing between ventricles</p> Signup and view all the answers

    What fills the pericardial cavity?

    <p>Pericardial fluid</p> Signup and view all the answers

    Which layer of the heart is directly involved in reducing friction during heart contractions?

    <p>Visceral layer of the serous pericardium</p> Signup and view all the answers

    Which structure connects the papillary muscles to the heart valves?

    <p>Chordae tendineae</p> Signup and view all the answers

    What is a function of the fibrous pericardium?

    <p>Protects the heart from external trauma</p> Signup and view all the answers

    Which structure prevents the valves in the heart from collapsing?

    <p>Chordae tendineae</p> Signup and view all the answers

    Which layer directly lines the heart chambers?

    <p>Endocardium</p> Signup and view all the answers

    How does the fibrous pericardium affect heart flexibility?

    <p>It restricts unnecessary overfilling</p> Signup and view all the answers

    What is the composition of the fibrous pericardium?

    <p>Dense fibrous connective tissue</p> Signup and view all the answers

    Which component is involved in anchoring the heart valves?

    <p>Chordae tendineae</p> Signup and view all the answers

    What is a primary characteristic of the endocardium?

    <p>It lines the inside of the heart chambers</p> Signup and view all the answers

    Which chamber of the heart is primarily responsible for pumping oxygenated blood to the body?

    <p>Left Ventricle</p> Signup and view all the answers

    Where is the tricuspid valve located in the heart?

    <p>Between the right atrium and right ventricle</p> Signup and view all the answers

    What structure separates the right and left ventricles?

    <p>Interventricular Septum</p> Signup and view all the answers

    Which of the following arteries is the first branch from the aortic arch?

    <p>Brachiocephalic Artery</p> Signup and view all the answers

    What is the primary role of the myocardium in the heart?

    <p>Contract and pump blood</p> Signup and view all the answers

    What type of blood does the right ventricle pump?

    <p>Deoxygenated blood to the pulmonary circuit</p> Signup and view all the answers

    What is the approximate size of the human heart?

    <p>About the size of a fist</p> Signup and view all the answers

    Which valve is located between the left atrium and left ventricle?

    <p>Bicuspid (Mitral) Valve</p> Signup and view all the answers

    Which layer of the heart is the outermost layer?

    <p>Epicardium</p> Signup and view all the answers

    Which structure carries deoxygenated blood from the heart to the lungs?

    <p>Pulmonary Arteries</p> Signup and view all the answers

    What is a primary function of the fibrous pericardium in relation to surrounding structures?

    <p>Anchoring the heart</p> Signup and view all the answers

    Which of the following best describes the protective role of the fibrous pericardium?

    <p>Preventing mechanical injury</p> Signup and view all the answers

    How does the fibrous pericardium contribute to cardiac function during high blood volume conditions?

    <p>It prevents the heart from overfilling</p> Signup and view all the answers

    What type of tissue primarily composes the fibrous pericardium?

    <p>Dense fibrous irregular connective tissue</p> Signup and view all the answers

    Which of the following is TRUE regarding the fibrous pericardium's impact on heart operation?

    <p>It stabilizes the heart's position</p> Signup and view all the answers

    What structure primarily acts as a separator between the left atrium and left ventricle?

    <p>Bicuspid (mitral) valve</p> Signup and view all the answers

    Which layer of the heart is responsible for the pumping action?

    <p>Myocardium</p> Signup and view all the answers

    What is the primary function of the chordae tendineae in the heart?

    <p>Prevent valve prolapse</p> Signup and view all the answers

    Which vessel carries oxygenated blood from the left ventricle to the body?

    <p>Aorta</p> Signup and view all the answers

    Which structure helps to separate the right and left ventricles?

    <p>Interventricular septum</p> Signup and view all the answers

    Which of the following correctly describes the location of the heart within the body?

    <p>Slightly to the left of the mid-sternal line</p> Signup and view all the answers

    What separates the right atrium from the left atrium?

    <p>Interatrial septum</p> Signup and view all the answers

    What is the primary role of the pericardial cavity?

    <p>Lubricate the heart and reduce friction</p> Signup and view all the answers

    What type of blood does the right atrium receive?

    <p>Deoxygenated blood from the body</p> Signup and view all the answers

    Which valve prevents backflow of blood from the pulmonary trunk into the right ventricle?

    <p>Pulmonary semilunar valve</p> Signup and view all the answers

    What is the correct phase of the cardiac cycle where blood is ejected from the ventricles?

    <p>Ventricular Ejection</p> Signup and view all the answers

    During which phase of the cardiac cycle do the AV valves close, creating the first heart sound?

    <p>Isovolumetric Contraction</p> Signup and view all the answers

    What occurs during the isovolumetric relaxation phase?

    <p>Ventricles are relaxing and coronary arteries fill with blood</p> Signup and view all the answers

    What occurs during the Isovolumetric Relaxation phase of the cardiac cycle?

    <p>Semilunar valves close</p> Signup and view all the answers

    What is the primary reason that semilunar valves remain closed during Isovolumetric Contraction?

    <p>Ventricular pressure is lower than arterial pressure</p> Signup and view all the answers

    Which heart sound is produced when the semilunar valves snap shut?

    <p>S2</p> Signup and view all the answers

    What does the T wave on an EKG correspond to in the cardiac cycle?

    <p>Isovolumetric relaxation</p> Signup and view all the answers

    Which component of the cardiac cycle is associated with atrial depolarization?

    <p>P wave</p> Signup and view all the answers

    How much blood passively fills into the ventricles during mid to late ventricular diastole?

    <p>70-80%</p> Signup and view all the answers

    What happens to the ventricular pressure during isovolumetric relaxation phase?

    <p>It is still greater than atrial pressure</p> Signup and view all the answers

    Which phase occurs immediately after atrial contraction?

    <p>Isovolumetric Contraction</p> Signup and view all the answers

    What is the primary physiological role of this isovolumetric relaxation phase?

    <p>Allowing the coronary arteries to fill with blood</p> Signup and view all the answers

    What indicates the end of the ejection phase during the cardiac cycle?

    <p>Closure of the semilunar valves</p> Signup and view all the answers

    Which of the following accurately describes the state of the ventricles during isovolumetric relaxation?

    <p>They are relaxing and repolarizing</p> Signup and view all the answers

    What marks the end of the isovolumetric relaxation phase?

    <p>Ventricles begin to refill with blood</p> Signup and view all the answers

    What is a characteristic event of the Isovolumetric Contraction phase regarding pressure?

    <p>Ventricular pressure is less than arterial pressure</p> Signup and view all the answers

    During the isovolumetric relaxation phase, how does the pressure in the aorta compare to the ventricular pressure?

    <p>Aortic pressure is greater than ventricular pressure</p> Signup and view all the answers

    What is a brief rise in aortic pressure called that occurs due to the closure of the aortic semilunar valve?

    <p>Dicrotic Notch</p> Signup and view all the answers

    Which phase of the cardiac cycle directly follows isovolumetric relaxation?

    <p>Ventricular filling</p> Signup and view all the answers

    What occurs during isovolumetric relaxation in the heart?

    <p>All four heart valves remain closed.</p> Signup and view all the answers

    What causes the 'dub' sound (S2) in the cardiac cycle?

    <p>Closure of the semilunar valves.</p> Signup and view all the answers

    What does the T wave on an EKG represent?

    <p>Ventricular repolarization.</p> Signup and view all the answers

    How long does the entire cardiac cycle typically last?

    <p>0.8 seconds.</p> Signup and view all the answers

    What happens to the coronary arteries during isovolumetric relaxation?

    <p>They fill with blood.</p> Signup and view all the answers

    Why is the isovolumetric relaxation phase important in the cardiac cycle?

    <p>It leads to ventricular filling.</p> Signup and view all the answers

    What is the primary result of the ventricles relaxing during this phase?

    <p>Maintenance of constant ventricular volume.</p> Signup and view all the answers

    Which statement about the isovolumetric relaxation phase is true?

    <p>The volume in the ventricle is constant.</p> Signup and view all the answers

    What occurs during mid to late ventricular diastole?

    <p>Atrial pressure exceeds ventricular pressure, opening AV valves.</p> Signup and view all the answers

    What characterizes the isovolumetric contraction phase?

    <p>No blood is ejected from the ventricles.</p> Signup and view all the answers

    What happens during the ventricular ejection phase?

    <p>Semilunar valves open as ventricular pressure increases.</p> Signup and view all the answers

    What is the role of the P wave in an EKG?

    <p>It indicates atrial depolarization.</p> Signup and view all the answers

    What causes the first heart sound ('Lub' or S1)?

    <p>Closure of the AV valves.</p> Signup and view all the answers

    What leads to the closing of the semilunar valves during ventricular relaxation?

    <p>Decreasing ventricular pressure.</p> Signup and view all the answers

    Which event occurs after ventricular pressure exceeds arterial pressure?

    <p>Semilunar valves open.</p> Signup and view all the answers

    What does the dicrotic notch refer to?

    <p>A brief rise in aortic pressure.</p> Signup and view all the answers

    What is the main component of the myocardium responsible for muscle contraction?

    <p>Cardiomyocytes</p> Signup and view all the answers

    Which layer of the heart is also referred to as the epicardium?

    <p>Visceral pericardium</p> Signup and view all the answers

    What structure allows for rapid electrical signal transmission between cardiomyocytes?

    <p>Intercalated discs</p> Signup and view all the answers

    What condition is associated with inflammation of the myocardium?

    <p>Myocarditis</p> Signup and view all the answers

    Which component of the cardiovascular system is responsible for carrying oxygenated blood away from the heart?

    <p>Arteries</p> Signup and view all the answers

    What is the function of the pericardial space?

    <p>Separating the layers of pericardium</p> Signup and view all the answers

    What condition is characterized by the obstruction of lymphatics leading to swelling?

    <p>Lymphedema</p> Signup and view all the answers

    Which component is primarily involved in the formation of blood clots in veins?

    <p>Valves</p> Signup and view all the answers

    What is the main type of disease associated with the coronary arteries?

    <p>Coronary artery disease</p> Signup and view all the answers

    Which feature of cardiomyocytes allows for coordinated contraction in the heart?

    <p>Intercalated discs</p> Signup and view all the answers

    What is the primary responsibility of the myocardium?

    <p>Muscle contraction of the heart</p> Signup and view all the answers

    Which structure is responsible for allowing rapid electrolyte movement in cardiomyocytes?

    <p>Intercalated discs</p> Signup and view all the answers

    What is the role of the pericardial space?

    <p>Facilitating frictionless movement of the heart</p> Signup and view all the answers

    Which layer of the heart is primarily composed of endothelial cells?

    <p>Endocardium</p> Signup and view all the answers

    What condition is characterized by inflammation of the pericardium?

    <p>Pericarditis</p> Signup and view all the answers

    Which type of tissue is primarily found in the fibrous pericardium?

    <p>Connective tissue</p> Signup and view all the answers

    What is a common manifestation associated with capillary dysfunction?

    <p>Sepsis</p> Signup and view all the answers

    Which of the following structures aids in the electrical signal transmission in the heart?

    <p>Conduction system</p> Signup and view all the answers

    Which arteries are primarily affected by Peripheral Artery Disease?

    <p>Arteries and arterioles</p> Signup and view all the answers

    What is the primary function of the coronary arteries?

    <p>Supply blood to the heart muscle</p> Signup and view all the answers

    What is the primary role of the sinoatrial (SA) node in the heart?

    <p>To generate electrical impulses for heart contractions</p> Signup and view all the answers

    Which component of the cardiac conduction system acts as a gatekeeper, slowing the electrical signal?

    <p>Atrioventricular (AV) node</p> Signup and view all the answers

    Which blood vessel is primarily responsible for gas exchange in tissues?

    <p>Capillaries</p> Signup and view all the answers

    What triggers ventricular systole during the cardiac cycle?

    <p>Propagation of the electrical impulse from the SA node</p> Signup and view all the answers

    What is the main function of arteries in the cardiovascular system?

    <p>To carry blood away from the heart</p> Signup and view all the answers

    Which layer of the heart is primarily responsible for its pumping action?

    <p>Myocardium</p> Signup and view all the answers

    What is a significant characteristic of the pericardium?

    <p>It has multiple layers including serous layers.</p> Signup and view all the answers

    What role do the Purkinje fibers play in the cardiac conduction system?

    <p>Conduct the signal to the ventricles for contraction</p> Signup and view all the answers

    What happens during ventricular diastole?

    <p>AV valves open and blood enters the ventricles</p> Signup and view all the answers

    Which condition is specifically associated with the coronary arteries?

    <p>Coronary artery disease (CAD)</p> Signup and view all the answers

    What is the role of the coronary arteries?

    <p>They supply blood to the heart muscle.</p> Signup and view all the answers

    Which chamber of the heart pumps deoxygenated blood to the lungs?

    <p>Right ventricle</p> Signup and view all the answers

    Which valve prevents backflow of blood into the right atrium?

    <p>Tricuspid valve</p> Signup and view all the answers

    What separates the right and left ventricles of the heart?

    <p>Interventricular septum</p> Signup and view all the answers

    Which vessel carries oxygenated blood back to the heart from the lungs?

    <p>Pulmonary veins</p> Signup and view all the answers

    Which structure acts as a non-conductive barrier for electrical signals in the heart?

    <p>Fibrous skeleton</p> Signup and view all the answers

    What is the main artery of the body responsible for delivering oxygenated blood?

    <p>Aorta</p> Signup and view all the answers

    What prevents backward blood flow from the ventricles into the atria?

    <p>Atrioventricular valves</p> Signup and view all the answers

    Which chambers of the heart receive deoxygenated blood from the body?

    <p>Right atrium</p> Signup and view all the answers

    What do chordae tendineae connect in the heart?

    <p>Valves to papillary muscles</p> Signup and view all the answers

    What is the primary function of the thoracic duct in the lymphatic system?

    <p>To return lymph fluid to the bloodstream</p> Signup and view all the answers

    Which layer of the heart contains the contractile cardiomyocytes?

    <p>Myocardium</p> Signup and view all the answers

    Which part of the pericardium is fused to the fibrous pericardium?

    <p>Parietal pericardium</p> Signup and view all the answers

    What type of disease primarily affects the valves of the heart?

    <p>Endocarditis</p> Signup and view all the answers

    What structure is involved in the rapid transmission of electrical signals in the heart?

    <p>Intercalated discs</p> Signup and view all the answers

    Which component of the cardiovascular system can be significantly affected by lymphedema?

    <p>Lymphatics</p> Signup and view all the answers

    What structure serves as a potential space between the two layers of the serous pericardium?

    <p>Pericardial space</p> Signup and view all the answers

    Which type of disease typically involves multiple components of the cardiovascular system?

    <p>Congenital heart disease</p> Signup and view all the answers

    What are the contractile units within cardiomyocytes called?

    <p>Sarcomeres</p> Signup and view all the answers

    Which condition primarily affects the myocardium of the heart?

    <p>Myocarditis</p> Signup and view all the answers

    What initiates the electrical impulses that regulate heart contractions?

    <p>Sinoatrial node</p> Signup and view all the answers

    What is the effect of the atrioventricular node on the electrical impulses?

    <p>Delays the signal</p> Signup and view all the answers

    During which phase does ventricular contraction occur?

    <p>Ventricular systole</p> Signup and view all the answers

    What sound is associated with the closure of the atrioventricular valves?

    <p>S1</p> Signup and view all the answers

    What is the main function of capillaries?

    <p>To facilitate gas exchange</p> Signup and view all the answers

    What happens to the semilunar valves during ventricular diastole?

    <p>They close</p> Signup and view all the answers

    Which vessels are thicker-walled and more elastic than veins?

    <p>Arteries</p> Signup and view all the answers

    How does the coronary circulation provide redundancy in blood supply?

    <p>By having anastomoses</p> Signup and view all the answers

    Which component of the cardiac conduction system is responsible for rapidly delivering the electrical signal to the ventricles?

    <p>Purkinje fibers</p> Signup and view all the answers

    Which type of vessel serves as a blood reservoir?

    <p>Veins</p> Signup and view all the answers

    What is the primary purpose of the cardiovascular system?

    <p>To pump blood throughout the body</p> Signup and view all the answers

    Which chamber of the heart is responsible for receiving deoxygenated blood from the body?

    <p>Right atrium</p> Signup and view all the answers

    What separates the right and left ventricles in the heart?

    <p>Interventricular septum</p> Signup and view all the answers

    What role do the semilunar valves serve in the heart?

    <p>Control blood flow from the ventricles to the arteries</p> Signup and view all the answers

    Which artery primarily supplies the right ventricle with blood?

    <p>Right coronary artery</p> Signup and view all the answers

    In which part of the cardiovascular system does oxygenation of blood primarily occur?

    <p>In the lungs</p> Signup and view all the answers

    What is the function of the chordae tendineae in the heart?

    <p>Prevent backflow of blood into the atria</p> Signup and view all the answers

    Which vessel carries oxygenated blood back from the lungs to the heart?

    <p>Pulmonary veins</p> Signup and view all the answers

    What component of the heart is larger and thicker-walled due to its function?

    <p>Left ventricle</p> Signup and view all the answers

    What is the role of the coronary vessels?

    <p>Supply blood to the heart itself</p> Signup and view all the answers

    What is the primary function of the cardiovascular system?

    <p>Circulating blood throughout the body</p> Signup and view all the answers

    Which chamber of the heart is responsible for pumping oxygenated blood to the body?

    <p>Left ventricle</p> Signup and view all the answers

    What role do the heart valves serve?

    <p>Prevent backflow of blood</p> Signup and view all the answers

    What effect does sympathetic stimulation have on heart rate?

    <p>Increases heart rate</p> Signup and view all the answers

    Where is the sinoatrial (SA) node located?

    <p>Right atrium</p> Signup and view all the answers

    Which structure transports carbon dioxide for removal from the body?

    <p>Pulmonary artery</p> Signup and view all the answers

    What is the primary role of white blood cells in the cardiovascular system?

    <p>Facilitating immune responses</p> Signup and view all the answers

    What separates the atria from each other?

    <p>Interatrial septum</p> Signup and view all the answers

    Which of the following is a function of hormones transported by the cardiovascular system?

    <p>Regulating blood pressure</p> Signup and view all the answers

    What distinguishes the left ventricle from the right ventricle?

    <p>It is larger and thicker</p> Signup and view all the answers

    What is the function of the atrioventricular (AV) node in the heart's electrical conduction system?

    <p>It delays the signal for ventricular filling.</p> Signup and view all the answers

    Which artery supplies the lateral wall of the left ventricle?

    <p>Left circumflex artery</p> Signup and view all the answers

    During which phase of the cardiac cycle does blood flow from the atria into the ventricles?

    <p>Atrial systole</p> Signup and view all the answers

    What is the primary role of Purkinje fibers in the heart?

    <p>Conducting the signal rapidly through the ventricles</p> Signup and view all the answers

    What is true about the coronary arteries?

    <p>They branch off directly from the aorta.</p> Signup and view all the answers

    Which layer of the heart is responsible for the contractile function?

    <p>Myocardium</p> Signup and view all the answers

    What defines venous insufficiency?

    <p>Failure of veins to return blood to the heart effectively</p> Signup and view all the answers

    What role do the intercalated discs play in cardiomyocytes?

    <p>They allow rapid electrical signal transmission between cells.</p> Signup and view all the answers

    Which condition involves fluid accumulation within the pericardium?

    <p>Pericardial effusion</p> Signup and view all the answers

    What is the primary function of the lymphatic system?

    <p>Returns interstitial fluid to the bloodstream</p> Signup and view all the answers

    Which component of the cardiovascular system is responsible for fluid accumulation in the pericardial space?

    <p>Pericardial effusions</p> Signup and view all the answers

    Which layer of the heart is primarily made up of cardiac muscle cells?

    <p>Myocardium</p> Signup and view all the answers

    What is the primary function of the intercalated discs in cardiomyocytes?

    <p>To facilitate rapid electrical signal transmission</p> Signup and view all the answers

    Which cardiovascular condition affects the coronary arteries?

    <p>Coronary artery disease</p> Signup and view all the answers

    What is the role of lymphatics in the cardiovascular system?

    <p>Remove excess fluid from tissues</p> Signup and view all the answers

    Which type of heart disease involves inflammation of the myocardium?

    <p>Myocarditis</p> Signup and view all the answers

    Which functional component of the cardiovascular system includes arteries and veins?

    <p>Periphery</p> Signup and view all the answers

    Which layer of the pericardium is directly attached to the myocardium?

    <p>Visceral pericardium</p> Signup and view all the answers

    What is a common manifestation of sepsis in relation to the cardiovascular system?

    <p>Increased heart rate</p> Signup and view all the answers

    What structural feature connects the cardiomyocytes and aids in synchronized contractions?

    <p>Intercalated discs</p> Signup and view all the answers

    Which blood vessel category has the smallest diameter?

    <p>Capillaries</p> Signup and view all the answers

    What is primarily responsible for the high resistance to blood flow in arterioles?

    <p>Pre-capillary sphincters</p> Signup and view all the answers

    Which characteristic distinguishes veins from arteries?

    <p>Presence of valves</p> Signup and view all the answers

    What differentiates varicocele from other types of varicose veins?

    <p>They occur in the testes.</p> Signup and view all the answers

    Which of the following adaptations in veins helps facilitate blood return to the heart?

    <p>Muscular milking action</p> Signup and view all the answers

    What mechanism is involved in the respiratory pump to aid venous return?

    <p>Pressure changes during thoracic cavity expansion</p> Signup and view all the answers

    Which type of blood vessels primarily serve as exchange sites for gas, nutrients, and waste?

    <p>Capillaries</p> Signup and view all the answers

    In which blood vessel type is the tunica media notably thicker?

    <p>Muscular Distributing Arteries</p> Signup and view all the answers

    What condition is characterized by dilated, tortuous veins in the legs?

    <p>Varicose Veins</p> Signup and view all the answers

    What is a key feature of elastic conducting arteries that enables them to manage high systolic pressure?

    <p>High elasticity</p> Signup and view all the answers

    What primary function do arterioles serve in the circulatory system?

    <p>Regulate blood flow resistance to capillary beds.</p> Signup and view all the answers

    Which characteristic differentiates veins from arteries?

    <p>Veins contain valves to prevent backflow.</p> Signup and view all the answers

    What is the primary consequence of incompetent valves in veins?

    <p>Pooling of blood leading to varicose veins.</p> Signup and view all the answers

    What is the primary structural feature of capillaries that facilitates their function?

    <p>Lack of cellular barriers for efficient exchange.</p> Signup and view all the answers

    What role do the pre-capillary sphincters play in the vascular system?

    <p>Control blood flow into capillary beds.</p> Signup and view all the answers

    Which factor does NOT contribute to the return of blood in veins?

    <p>High pressure in venules.</p> Signup and view all the answers

    What is the average diameter of a muscular distributing artery?

    <p>6 millimeters.</p> Signup and view all the answers

    What condition is associated with varicose veins in the testicles?

    <p>Varicocele leading to testicular issues.</p> Signup and view all the answers

    What distinguishes elastic conducting arteries from other types of arteries?

    <p>They have a higher diameter than muscular arteries.</p> Signup and view all the answers

    Which statement best describes the characteristic of veins related to blood volume?

    <p>Veins have a larger lumen, increasing their capacitance.</p> Signup and view all the answers

    What is the primary function of the trachea?

    <p>To transport air to and from the lungs</p> Signup and view all the answers

    Which statement best describes the bronchi?

    <p>Each one branches into smaller bronchioles</p> Signup and view all the answers

    What role does the diaphragm play in respiration?

    <p>It assists in air movement during inhalation and exhalation</p> Signup and view all the answers

    Which of the following correctly describes bronchioles?

    <p>They are the smallest branches of bronchial tubes</p> Signup and view all the answers

    What happens during diaphragm contraction?

    <p>Oxygen is pulled into the lungs</p> Signup and view all the answers

    How does the diaphragm assist in non-respiratory functions?

    <p>By increasing intra-abdominal pressure</p> Signup and view all the answers

    What is the anatomical position of the trachea relative to the larynx?

    <p>Below the larynx</p> Signup and view all the answers

    Which statement is true regarding gas exchange in the bronchi?

    <p>It happens in the alveoli only</p> Signup and view all the answers

    What effect does the relaxation of the diaphragm have during exhalation?

    <p>It increases air pressure in the lungs</p> Signup and view all the answers

    What is the approximate number of bronchioles in each lung?

    <p>30,000</p> Signup and view all the answers

    What is the primary function of the respiratory system?

    <p>To carry oxygen to the bloodstream and expel carbon dioxide</p> Signup and view all the answers

    Which structures are involved in the process of inhalation?

    <p>Diaphragm and external intercostal muscles</p> Signup and view all the answers

    What is the significance of alveoli in the respiratory system?

    <p>They are responsible for gas exchange between the bloodstream and the air</p> Signup and view all the answers

    How do the lungs assist in regulating blood pH?

    <p>By managing carbon dioxide levels in the bloodstream</p> Signup and view all the answers

    What is the pathway of oxygen from the environment to the bloodstream?

    <p>Mouth &gt; Trachea &gt; Alveoli &gt; Capillaries &gt; Bloodstream</p> Signup and view all the answers

    Which component is NOT part of the respiratory system?

    <p>Esophagus</p> Signup and view all the answers

    What happens during the process of exhalation?

    <p>Carbon dioxide follows the same path out of the lungs</p> Signup and view all the answers

    What is the anatomical location of the lungs?

    <p>Within the chest cavity on either side of the heart</p> Signup and view all the answers

    What type of tissue primarily composes the lungs?

    <p>Spongy, elastic tissue</p> Signup and view all the answers

    Which function is primarily ascribed to the bronchi?

    <p>To transport air into the lungs from the trachea</p> Signup and view all the answers

    What is the primary function of the respiratory system?

    <p>To supply blood with oxygen</p> Signup and view all the answers

    Which of the following correctly describes inhalation?

    <p>It occurs through the diaphragm and external intercostal muscles</p> Signup and view all the answers

    What structure connects the trachea to the lungs?

    <p>Bronchi</p> Signup and view all the answers

    What role do alveoli play in the respiratory system?

    <p>They serve as the site of gas exchange</p> Signup and view all the answers

    Which statement is true regarding the lungs?

    <p>They assist in regulating blood pH</p> Signup and view all the answers

    During exhalation, where does carbon dioxide pass from the bloodstream?

    <p>To the trachea and then to the mouth</p> Signup and view all the answers

    How many alveoli does the average adult's lungs contain?

    <p>About 600 million</p> Signup and view all the answers

    Which muscles are primarily responsible for initiating inhalation?

    <p>Diaphragm and external intercostal muscles</p> Signup and view all the answers

    What is one characteristic of the tissue composing the respiratory airways?

    <p>It contains cartilage and smooth muscle</p> Signup and view all the answers

    What happens to the airways during respiration?

    <p>They are able to constrict and expand</p> Signup and view all the answers

    What is the primary function of the trachea in the respiratory system?

    <p>To serve as the main passageway for air to and from the lungs</p> Signup and view all the answers

    Which statement accurately describes the structure of the bronchi?

    <p>Each bronchus branches into smaller bronchial tubes</p> Signup and view all the answers

    What happens during the contraction of the diaphragm?

    <p>Oxygen is pulled into the lungs</p> Signup and view all the answers

    Why is exhalation primarily considered a passive process?

    <p>It occurs without muscle contraction in normal breathing</p> Signup and view all the answers

    What role does the diaphragm play in non-respiratory functions?

    <p>It helps to expel vomit and feces from the body</p> Signup and view all the answers

    Which of the following correctly describes the bronchioles?

    <p>They have a similar thickness to a hair</p> Signup and view all the answers

    What effect does the relaxation of the diaphragm have during breathing?

    <p>It helps pump carbon dioxide out of the lungs</p> Signup and view all the answers

    What happens to the airways as the bronchus branches further?

    <p>They continuously narrow into smaller tubes</p> Signup and view all the answers

    What is the significance of exhalation during forced breathing?

    <p>It requires the aid of expiratory muscles</p> Signup and view all the answers

    What distinguishes bronchi from bronchioles in terms of their functions?

    <p>Bronchioles assist in gas exchange while bronchi do not</p> Signup and view all the answers

    Which of the following describes an end artery?

    <p>An artery that is the only source of blood supply to a specific area</p> Signup and view all the answers

    What is the main function of large arteries during diastole?

    <p>To store and release energy effectively</p> Signup and view all the answers

    Which arteries serve as a primary source for oxygenated blood to the brain?

    <p>Internal carotid arteries</p> Signup and view all the answers

    What distinguishes small arteries from medium-sized arteries?

    <p>Small arteries typically have 8-10 layers of smooth muscle cells</p> Signup and view all the answers

    What is the primary function of the vertebral artery as it relates to the brain?

    <p>To supply the hindbrain and cervical spinal cord</p> Signup and view all the answers

    What feature is unique to the external carotid artery?

    <p>It supplies the tongue and face structures</p> Signup and view all the answers

    Which of the following arteries is responsible for supplying the muscles of mastication?

    <p>Superficial temporal artery</p> Signup and view all the answers

    Which of the following statements is true regarding the lumen of arteries compared to veins?

    <p>Arterial lumens are typically rounded and firm</p> Signup and view all the answers

    Which anatomical feature is primarily responsible for the division of the maxillary artery into its parts?

    <p>Scalenus anterior muscle</p> Signup and view all the answers

    Which branch of the subclavian artery is crucial for establishing collateral circulation for the brain?

    <p>Vertebral artery</p> Signup and view all the answers

    Which type of artery primarily conducts blood to medium-sized distributing arteries?

    <p>Elastic arteries</p> Signup and view all the answers

    What characteristic of the tunica media is most predominant in medium-sized arteries?

    <p>Smooth muscle</p> Signup and view all the answers

    What is a key feature of the course of the superficial temporal artery?

    <p>Ascends to the root of the neck and arches laterally</p> Signup and view all the answers

    Which artery supplies the 3rd to 11th posterior intercostal arteries?

    <p>Parietal branch of the thoracic aorta</p> Signup and view all the answers

    What is the primary role of the internal mammary artery in relation to the thorax?

    <p>Provides branches to the upper 6 intercostal spaces</p> Signup and view all the answers

    Which artery is NOT a branch of the subclavian artery that supplies the thorax?

    <p>Inferior phrenic artery</p> Signup and view all the answers

    Which arteries supply the anterior intercostal spaces from 7th to 11th intercostal spaces?

    <p>Musculophrenic arteries</p> Signup and view all the answers

    What is the function of the azygos venous system?

    <p>To drain blood from the thoracic wall</p> Signup and view all the answers

    Which artery supplies the diaphragm directly?

    <p>Inferior phrenic artery</p> Signup and view all the answers

    Which artery gives off the upper two posterior intercostal arteries?

    <p>Costocervical artery</p> Signup and view all the answers

    What is true regarding the first and second intercostal arteries?

    <p>They arise from the subclavian artery.</p> Signup and view all the answers

    Which of the following arteries does NOT originate from the branches of the subclavian artery?

    <p>Thoracic aortic artery</p> Signup and view all the answers

    What is the function of the superior phrenic artery?

    <p>It supplies the diaphragm.</p> Signup and view all the answers

    What is the primary function of the cephalic vein in the upper extremity?

    <p>Drains into the axillary vein</p> Signup and view all the answers

    What does the basilic vein do halfway up the arm?

    <p>It joins the venae comitantes of the brachial artery</p> Signup and view all the answers

    Where is the median cubital vein located?

    <p>In the cubital fossa</p> Signup and view all the answers

    What comprises the palmar arterial anastomosis?

    <p>Two anastomotic arches formed by radial and ulnar arteries</p> Signup and view all the answers

    Which artery predominantly supplies blood to the hand?

    <p>Radial artery</p> Signup and view all the answers

    Which vein acts as a communication between the cephalic vein and basilic vein?

    <p>Median cubital vein</p> Signup and view all the answers

    What does the lateral cord of the brachial plexus indicate about its location?

    <p>It is located laterally to the second part of the axillary artery</p> Signup and view all the answers

    How does the basilic vein drain into the axillary vein?

    <p>Joining the venae comitantes of the brachial artery</p> Signup and view all the answers

    Which veins are responsible for venous drainage in the upper extremity?

    <p>Cephalic, basilic, and median cubital veins</p> Signup and view all the answers

    What does palmar arterial anastomosis primarily provide to the hand?

    <p>Collateral blood supply</p> Signup and view all the answers

    What is the primary function of the axillary artery?

    <p>Conveys oxygenated blood to the upper limb</p> Signup and view all the answers

    Where does the brachial artery begin its course?

    <p>At the lower margin of the teres major muscle</p> Signup and view all the answers

    What branches off the brachial artery?

    <p>Deep brachial artery and nutritional branches</p> Signup and view all the answers

    What is the role of the superior thoracic artery?

    <p>It supplies the first two intercostal spaces</p> Signup and view all the answers

    Why is the subclavian artery significant in the context of brachial and axillary anatomy?

    <p>It continues as the brachial artery after the teres major.</p> Signup and view all the answers

    What structure lies behind the pectoralis minor muscle?

    <p>The axillary artery</p> Signup and view all the answers

    What are the terminal branches of the brachial artery?

    <p>Radial and ulnar arteries</p> Signup and view all the answers

    What is the anatomical position of the first part of the axillary artery?

    <p>From the lateral border of the first rib to the pectoralis minor</p> Signup and view all the answers

    What arteries do the profunda brachii artery primarily supply?

    <p>Deep structures of the arm</p> Signup and view all the answers

    What is true about the branches of the axillary artery?

    <p>They include branches for both the arm and shoulder.</p> Signup and view all the answers

    What structure does the internal jugular vein join to form the brachiocephalic vein?

    <p>Subclavian vein</p> Signup and view all the answers

    Which of the following tributaries is associated with the internal jugular vein?

    <p>Inferior petrosal sinus</p> Signup and view all the answers

    What is located directly above the inferior bulb of the internal jugular vein?

    <p>Bicuspid valve</p> Signup and view all the answers

    What is the anterior relationship of the subclavian vein?

    <p>Clavicle</p> Signup and view all the answers

    Which vein is often received by the subclavian vein?

    <p>External jugular vein</p> Signup and view all the answers

    Which muscle is located posteriorly to the subclavian vein?

    <p>Scalenus anterior</p> Signup and view all the answers

    What is the continuation of the axillary vein called?

    <p>Subclavian vein</p> Signup and view all the answers

    Which of the following is NOT a tributary of the internal jugular vein?

    <p>Posterior communicating vein</p> Signup and view all the answers

    Where does the small saphenous vein drain into?

    <p>Popliteal vein</p> Signup and view all the answers

    Which statement correctly describes the origin of the great saphenous vein?

    <p>Originates from the dorsal vein of the first digit merging with the dorsal venous arch</p> Signup and view all the answers

    Which artery is described as the terminal branch of the popliteal artery?

    <p>Anterior tibial artery</p> Signup and view all the answers

    How does the anterior tibial artery initially travel in the leg?

    <p>Between the heads of gastrocnemius muscle</p> Signup and view all the answers

    What anatomical location does the great saphenous vein run over at the knee?

    <p>Posterior border of the medial epicondyle</p> Signup and view all the answers

    What is the primary function of systemic circulation?

    <p>Carries oxygenated blood to the body</p> Signup and view all the answers

    What is the composition of the tunica media in arteries?

    <p>Muscle tissue and elastic fibers</p> Signup and view all the answers

    Which structure is NOT part of the pulmonary circulation?

    <p>Aorta</p> Signup and view all the answers

    What differentiates veins from arteries structurally?

    <p>Veins have collapsed appearance</p> Signup and view all the answers

    What is the pathway of blood in the pulmonary circulation?

    <p>RV → Pulmonary artery → Lungs → Pulmonary vein</p> Signup and view all the answers

    Which artery is NOT included in the major trunks of systemic circulation?

    <p>Pulmonary trunk</p> Signup and view all the answers

    Which layer of blood vessels is composed of connective tissue?

    <p>Tunica adventitia</p> Signup and view all the answers

    What anatomical location corresponds to the bifurcation of the common iliac arteries?

    <p>Level of L4 vertebra</p> Signup and view all the answers

    What is the function of the hepatic portal circulation?

    <p>Carries blood from the GI tract to the liver</p> Signup and view all the answers

    Which branches are associated with the splenic artery?

    <p>Pancreatic and short gastric arteries</p> Signup and view all the answers

    What is a notable feature of the splenic artery's path?

    <p>Tortuosity of its course</p> Signup and view all the answers

    Which of the following best describes the vessel wall of capillaries?

    <p>Thin, allowing for gas exchange</p> Signup and view all the answers

    What is the origin point of the splenic artery?

    <p>Celiac artery</p> Signup and view all the answers

    What type of blood do pulmonary veins carry?

    <p>Oxygenated blood</p> Signup and view all the answers

    Which arteries are described as paired and usually numbering four in the posterior abdominal wall?

    <p>Lumbar arteries</p> Signup and view all the answers

    What is the typical anatomical feature of the pancreatic branches of the splenic artery?

    <p>They enter the hilus of the spleen</p> Signup and view all the answers

    What anatomical feature distinguishes the median sacral arteries?

    <p>Passes inferiorly across lumbar vertebrae</p> Signup and view all the answers

    What is the role of the short gastric arteries?

    <p>Supply blood to the greater curvature of the stomach</p> Signup and view all the answers

    Where do the pancreatic branches of the splenic artery typically lead?

    <p>To the tissues of the spleen</p> Signup and view all the answers

    What term is used to describe the point where the common iliac arteries split?

    <p>Bifurcation</p> Signup and view all the answers

    What is a primary function of the azygos vein?

    <p>To serve as an alternate pathway when the superior or inferior vena cava is blocked</p> Signup and view all the answers

    Where does the azygos vein primarily lie in relation to the thoracic vertebrae?

    <p>On the right side of the thoracic vertebral column</p> Signup and view all the answers

    From which veins is the azygos vein formed?

    <p>Ascending lumbar veins and right subcostal veins</p> Signup and view all the answers

    What anatomical landmark is associated with the azygos vein?

    <p>Arch of the azygos vein</p> Signup and view all the answers

    What characteristic distinguishes the azygos vein from the hemiazygos vein?

    <p>It is the only unpaired vein in this region</p> Signup and view all the answers

    Where does the azygos vein arch over before it joins the superior vena cava?

    <p>Posteriorly at the root of the right lung</p> Signup and view all the answers

    Which feature is characteristic of the hemiazygos vein?

    <p>It is considered a tributary to the azygos vein</p> Signup and view all the answers

    What is an unusual variation that may occur with the azygos vein?

    <p>The arch can be displaced laterally</p> Signup and view all the answers

    What is the primary role of the anterior intercostal arteries?

    <p>To supply blood to the thoracic wall</p> Signup and view all the answers

    How many anterior intercostal arteries arise from the internal thoracic artery?

    <p>12 arteries, 2 in each of the upper six intercostal spaces</p> Signup and view all the answers

    Which artery is associated with the internal thoracic artery?

    <p>Musculophrenic artery</p> Signup and view all the answers

    What is the primary route of the internal thoracic artery?

    <p>Runs caudally behind the anterior chest wall</p> Signup and view all the answers

    Which artery does NOT branch from the thyrocervical trunk?

    <p>Musculophrenic artery</p> Signup and view all the answers

    What branches does the thyrocervical trunk divide into?

    <p>Inferior thyroid, suprascapular, and transverse cervical arteries</p> Signup and view all the answers

    Where does the internal thoracic artery give off perforating vessels?

    <p>To the intercostal spaces</p> Signup and view all the answers

    What is the relationship between the internal thoracic artery and the superior epigastric artery?

    <p>The internal thoracic artery terminates in the superior epigastric artery</p> Signup and view all the answers

    Which area does the suprascapular artery primarily supply?

    <p>Posterior shoulder region</p> Signup and view all the answers

    Which term refers to the internal thoracic artery?

    <p>Internal mammary artery</p> Signup and view all the answers

    What is the continuation of the anterior tibial artery distal to the ankle?

    <p>Dorsalis pedis</p> Signup and view all the answers

    What is the termination point of the popliteal artery?

    <p>Anterior tibial artery and posterior tibial artery</p> Signup and view all the answers

    Which of the following arteries is not a branch of the popliteal artery?

    <p>Dorsalis pedis</p> Signup and view all the answers

    Which artery passes to the proximal end of the first intermetatarsal space?

    <p>Dorsalis pedis</p> Signup and view all the answers

    Which structure is easily palpated due to its position?

    <p>Popliteal artery</p> Signup and view all the answers

    What condition results in increased resistance to blood flow in the portal system?

    <p>Portal hypertension</p> Signup and view all the answers

    Which blood vessel can form an anastomosis with the splenic vein after a splenectomy?

    <p>Left renal vein</p> Signup and view all the answers

    What is the main purpose of porto-caval shunts in treating portal hypertension?

    <p>To allow blood to flow past the portal vein</p> Signup and view all the answers

    Which vessels are involved in forming a collateral circulation in the upper extremity?

    <p>Transverse cervical artery and branches of the thoracic aorta</p> Signup and view all the answers

    What complication often accompanies the enlargement of the portal-systemic connections?

    <p>Congestive enlargement of the spleen</p> Signup and view all the answers

    What anatomical feature allows blood to continue circulating if the subclavian artery is obstructed?

    <p>Collateral circulation</p> Signup and view all the answers

    Which artery is NOT involved in the collateral circulation around the scapula?

    <p>Brachiocephalic artery</p> Signup and view all the answers

    The portal vein may anastomose with which part of the inferior vena cava?

    <p>Anterior wall behind the lesser sac</p> Signup and view all the answers

    What represents a consequence of portal hypertension?

    <p>Forceful blood rerouting to alternate channels</p> Signup and view all the answers

    Which part of the circulatory system is primarily affected by portal hypertension?

    <p>Portal vein and its tributaries</p> Signup and view all the answers

    What does the thoracoepigastric vein primarily connect?

    <p>The lateral thoracic vein and the superficial epigastric vein</p> Signup and view all the answers

    Where does the accessory hemiazygos vein begin?

    <p>At the medial end of the 4th or 5th intercostal space</p> Signup and view all the answers

    What is the significance of the thoracoepigastric vein during inferior vena cava obstruction?

    <p>It provides collateral venous return</p> Signup and view all the answers

    Which structure does the accessory hemiazygos vein join?

    <p>The hemiazygos vein</p> Signup and view all the answers

    What type of veins does the thoracoepigastric vein receive?

    <p>Several small mediastinal branches and inferior oesophageal veins</p> Signup and view all the answers

    Which vertebrae does the accessory hemiazygos vein cross over to join the azygos vein?

    <p>T7 or T8</p> Signup and view all the answers

    What notable condition is associated with the thoracoepigastric vein?

    <p>Mondor's disease</p> Signup and view all the answers

    The accessory hemiazygos vein primarily collects tributaries from which intercostal spaces?

    <p>Fourth to eighth intercostal spaces</p> Signup and view all the answers

    What muscles are supplied by the arteries associated with the thoracoepigastric vein?

    <p>Muscles of the abdominal wall</p> Signup and view all the answers

    What is the alternative name for the inferior three intercostal veins received by the thoracoepigastric vein?

    <p>Subcostal veins</p> Signup and view all the answers

    What is the function of porto-caval anastomosis?

    <p>To provide alternative pathways for blood flow when the direct route is blocked</p> Signup and view all the answers

    Which veins are involved in the anastomosis at the lower third of the esophagus?

    <p>Left gastric vein and esophageal veins</p> Signup and view all the answers

    Where do the paraumbilical veins connect?

    <p>With the superficial veins of the anterior abdominal wall</p> Signup and view all the answers

    Which tributaries are involved in the anastomosis halfway down the anal canal?

    <p>Superior rectal veins and middle and inferior rectal veins</p> Signup and view all the answers

    What is the general pathway of portal venous blood under normal conditions?

    <p>From the liver to the inferior vena cava</p> Signup and view all the answers

    Which vein is NOT a tributary of the portal vein?

    <p>Internal iliac vein</p> Signup and view all the answers

    Which of the following veins contribute to the anastomosis in the ascending colon area?

    <p>Veins of the ascending colon and systemic tributaries like renal veins</p> Signup and view all the answers

    What is the primary function of the splenic vein?

    <p>To carry blood from the spleen to the inferior vena cava</p> Signup and view all the answers

    What is NOT an outcome of blocked portal circulation?

    <p>Increased blood drainage through the inferior vena cava</p> Signup and view all the answers

    Which arteries contribute to scapular arterial anastomosis?

    <p>Humeral circumflex arteries and thoracodorsal artery</p> Signup and view all the answers

    What condition is characterized by hypertension in the portal vein and its tributaries?

    <p>Portal hypertension</p> Signup and view all the answers

    Which of the following vessels is NOT involved in the anastomosis around the scapula?

    <p>Superior mesenteric artery</p> Signup and view all the answers

    What is the primary function of the porto-caval anastomosis?

    <p>To allow blood to flow past the joint</p> Signup and view all the answers

    Which vein may be anastomosed to the left renal vein after a spleen removal procedure?

    <p>Splenic vein</p> Signup and view all the answers

    What happens to the blood if the subclavian artery is obstructed?

    <p>Collateral circulation allows continued blood flow</p> Signup and view all the answers

    What is the primary vein involved in draining the face into the internal jugular vein?

    <p>Facial vein</p> Signup and view all the answers

    Which artery is NOT a branch of the internal carotid artery?

    <p>Common carotid artery</p> Signup and view all the answers

    What anatomical structure does the facial vein form from?

    <p>Supraorbital and supratrochlear veins</p> Signup and view all the answers

    Which structure accompanies the superficial temporal vein?

    <p>Auriculotemporal artery</p> Signup and view all the answers

    What connects the facial vein with the cavernous sinus?

    <p>Ophthalmic veins</p> Signup and view all the answers

    Which artery is a part of the Circle of Willis?

    <p>Anterior cerebral artery</p> Signup and view all the answers

    Which feature is associated with the formation of the facial vein?

    <p>Descends alongside the facial artery</p> Signup and view all the answers

    Which of the following arteries does NOT branch directly from the internal carotid artery?

    <p>Posterior cerebral artery</p> Signup and view all the answers

    Which vein is formed by the joining of the subclavian vein with the internal jugular vein?

    <p>Brachiocephalic vein</p> Signup and view all the answers

    What is located directly above the inferior bulb of the internal jugular vein?

    <p>Bicuspid valve</p> Signup and view all the answers

    Which muscle is located posteriorly to the subclavian vein?

    <p>Scalenus anterior muscle</p> Signup and view all the answers

    Which tributary is NOT associated with the internal jugular vein?

    <p>Subclavian vein</p> Signup and view all the answers

    Which vein does the subclavian vein often receive on the left side?

    <p>Thoracic duct</p> Signup and view all the answers

    What anatomical structure does the subclavian vein join to contribute to the formation of the brachiocephalic vein?

    <p>Internal jugular vein</p> Signup and view all the answers

    The internal jugular vein descends in the carotid sheath. Which of the following structures is it located lateral to?

    <p>Common carotid arteries</p> Signup and view all the answers

    Which of the following veins is a tributary of the internal jugular vein?

    <p>Lingual vein</p> Signup and view all the answers

    Which artery runs caudally behind the anterior thoracic wall and gives off anterior intercostal branches?

    <p>Internal thoracic artery</p> Signup and view all the answers

    What is the primary termination point of the internal thoracic artery?

    <p>Superior epigastric artery</p> Signup and view all the answers

    What type of branches does the thoracic aorta give off?

    <p>Visceral branches</p> Signup and view all the answers

    Which of the following arteries is NOT a branch of the thyrocervical trunk?

    <p>Musculophrenic artery</p> Signup and view all the answers

    Which structure is closely related to the internal jugular vein?

    <p>Deep cervical lymph nodes</p> Signup and view all the answers

    The thyrocervical trunk primarily supplies which area of the body?

    <p>Lower neck and shoulder</p> Signup and view all the answers

    What is one of the branches that arises from the thyrocervical trunk?

    <p>Suprascapular artery</p> Signup and view all the answers

    Which artery is responsible for supplying the thyroid gland among the branches of the thyrocervical trunk?

    <p>Inferior thyroid artery</p> Signup and view all the answers

    Which artery is known as the internal mammary artery?

    <p>Internal thoracic artery</p> Signup and view all the answers

    What type of branches does the internal thoracic artery give off to supply the breast?

    <p>Perforating vessels</p> Signup and view all the answers

    In which area does the internal thoracic artery primarily provide blood supply?

    <p>Anterior chest wall</p> Signup and view all the answers

    Which of these arteries is a branch that arises from the internal thoracic artery?

    <p>Perforating branches</p> Signup and view all the answers

    Which organ is drained by the renal vein?

    <p>Kidney</p> Signup and view all the answers

    What area is drained by the inferior phrenic vein?

    <p>Diaphragm</p> Signup and view all the answers

    What is the pathway of blood from the portal vein after it enters the liver?

    <p>It passes through the hepatic veins</p> Signup and view all the answers

    Which region does the gonadal vein primarily drain?

    <p>Ovaries / testes</p> Signup and view all the answers

    Where does the inferior vena cava enter the heart?

    <p>Lower right atrium</p> Signup and view all the answers

    What tributary drains blood from the adrenal glands?

    <p>Suprarenal vein</p> Signup and view all the answers

    What does the portal vein primarily drain?

    <p>Spleen and pancreas</p> Signup and view all the answers

    What runs along the side of the vertebral column?

    <p>Inferior vena cava</p> Signup and view all the answers

    Which vein drains the lumbar portion of the abdomen?

    <p>Lumbar veins</p> Signup and view all the answers

    Where does blood from the hepatic veins ultimately go?

    <p>Inferior vena cava</p> Signup and view all the answers

    What is formed by the union of the superficial temporal vein and the maxillary vein?

    <p>Retromandibular vein</p> Signup and view all the answers

    Which vein descends in front of the neck close to the midline?

    <p>Anterior jugular vein</p> Signup and view all the answers

    What is the primary drainage location of the external jugular vein?

    <p>Subclavian vein</p> Signup and view all the answers

    At which vertebral level does the descending thoracic aorta commence?

    <p>T4</p> Signup and view all the answers

    What does the retromandibular vein divide into upon leaving the parotid salivary gland?

    <p>Anterior branch and posterior branch</p> Signup and view all the answers

    The internal jugular vein leaves the skull through which foramen?

    <p>Jugular foramen</p> Signup and view all the answers

    Which vein is formed by the union of the posterior auricular vein and the posterior division of the retromandibular vein?

    <p>External jugular vein</p> Signup and view all the answers

    Which vein receives blood mainly from the brain, face, and neck?

    <p>Internal jugular vein</p> Signup and view all the answers

    What does the artery become as it passes through the opening in the adductor magnus?

    <p>Popliteal artery</p> Signup and view all the answers

    Which of the following is NOT a branch of the mentioned artery?

    <p>Deep external iliac</p> Signup and view all the answers

    What structure do the terminal branches of this artery form under?

    <p>Abductor hallucis</p> Signup and view all the answers

    Where does the artery descend medially in relation to the tibia?

    <p>Posterior to the tibialis posterior</p> Signup and view all the answers

    What is one of the terminal branches of the artery mentioned?

    <p>Medial plantar</p> Signup and view all the answers

    What is the primary function of the azygos vein?

    <p>To serve as an alternate pathway if the superior vena cava is blocked</p> Signup and view all the answers

    Where is the azygos vein primarily located?

    <p>Right side of the thoracic vertebral column</p> Signup and view all the answers

    At what anatomical level does the azygos vein form?

    <p>At the level of the 12th thoracic vertebra</p> Signup and view all the answers

    Which structure does the azygos vein arch over?

    <p>Right main bronchus</p> Signup and view all the answers

    What is an important anatomical landmark associated with the azygos vein?

    <p>Arch of the azygos vein</p> Signup and view all the answers

    What characteristic does the azygos vein have in comparison to other veins?

    <p>It is considered unpaired and mostly located on the right side</p> Signup and view all the answers

    What does the azygos vein drain?

    <p>The back, thoracic, and abdominal walls</p> Signup and view all the answers

    What are the tributaries to the azygos vein?

    <p>Hemiazygos vein and its accessory branches</p> Signup and view all the answers

    What anatomical variation can occur with the arch of the azygos vein?

    <p>It can be displaced laterally, creating a pleural septum</p> Signup and view all the answers

    How does the azygos vein facilitate blood flow during a blockage?

    <p>By providing an alternative pathway to the right atrium</p> Signup and view all the answers

    What defines the location of the abdominal aorta's beginning?

    <p>At the level of the diaphragm and T12 vertebra</p> Signup and view all the answers

    What characterizes the terminal branches of the abdominal aorta?

    <p>They include both paired and unpaired branches</p> Signup and view all the answers

    Which branch of the abdominal aorta is classified as unpaired?

    <p>Celiac artery</p> Signup and view all the answers

    Which lumbar vertebra is the most convex part of the vertebral column in relation to the abdominal aorta?

    <p>L4</p> Signup and view all the answers

    What is the role of visceral branches of the abdominal aorta?

    <p>Supplying internal organs</p> Signup and view all the answers

    Which artery supplies the adrenal glands?

    <p>Middle suprarenal artery</p> Signup and view all the answers

    What do posterior or parietal branches of the abdominal aorta supply?

    <p>Diaphragm or body wall</p> Signup and view all the answers

    Which of the following pairs are visceral branches of the abdominal aorta?

    <p>Celiac and Renal arteries</p> Signup and view all the answers

    Where does the abdominal aorta travel once it begins at the diaphragm?

    <p>Down the posterior wall of the abdomen</p> Signup and view all the answers

    What structure is often associated or connected with the accessory azygos vein?

    <p>Superior intercostal vein</p> Signup and view all the answers

    Which artery is considered the smallest of the celiac trunk branches?

    <p>Left gastric artery</p> Signup and view all the answers

    What structure does the left gastric artery anastomose with?

    <p>Aortic esophageal arteries</p> Signup and view all the answers

    Which artery branches upward from the celiac trunk to supply the abdominal foregut?

    <p>Left gastric artery</p> Signup and view all the answers

    What is the primary function of the inferior mesenteric artery?

    <p>Supply the abdominal hindgut</p> Signup and view all the answers

    Which artery is the largest among the three branches of the celiac trunk in adults?

    <p>Hepatic artery</p> Signup and view all the answers

    Which artery is primarily responsible for supplying the kidneys?

    <p>Renal artery</p> Signup and view all the answers

    What is supplied by the branches of the superior mesenteric artery?

    <p>Abdominal midgut</p> Signup and view all the answers

    Which arteries supply the ovaries in females?

    <p>Gonadal arteries</p> Signup and view all the answers

    What does the gastroduodenal artery supply?

    <p>Stomach and duodenum</p> Signup and view all the answers

    Which artery is positioned immediately superior to the renal arteries?

    <p>Middle suprarenal arteries</p> Signup and view all the answers

    Which vein drains blood from the adrenal glands into the inferior vena cava?

    <p>Suprarenal vein</p> Signup and view all the answers

    Which organ is drained by the hepatic veins that ultimately connect to the inferior vena cava?

    <p>Liver</p> Signup and view all the answers

    What is one area drained by the lumbar veins?

    <p>Lumbar portion of the abdomen</p> Signup and view all the answers

    Which vessel runs alongside the vertebral column on its right side in the abdominal cavity?

    <p>Inferior vena cava</p> Signup and view all the answers

    What part of the gastrointestinal tract is primarily drained by the portal vein?

    <p>Whole gastrointestinal tract</p> Signup and view all the answers

    What area does the internal carotid artery supply?

    <p>The brain and part of the nose</p> Signup and view all the answers

    Which structure does the internal carotid artery ascend with in the neck?

    <p>The vagus nerve</p> Signup and view all the answers

    At what anatomical point does the internal carotid artery begin?

    <p>At the bifurcation of the common carotid artery</p> Signup and view all the answers

    Which part does the dorsal scapular artery come from?

    <p>Second part of the costocervical trunk</p> Signup and view all the answers

    What is the role of the deep cervical artery?

    <p>To supply the deep muscles of the neck</p> Signup and view all the answers

    Where does the internal carotid artery leave the neck?

    <p>Via the carotid canal in the temporal bone</p> Signup and view all the answers

    Which muscle groups does the dorsal scapular artery primarily supply?

    <p>The rhomboids and levator scapulae</p> Signup and view all the answers

    What occurs when the internal carotid artery passes deep to the parotid salivary gland?

    <p>It becomes embedded in the carotid sheath</p> Signup and view all the answers

    What is the term for the secondary or accessory circulation that provides multiple pathways for blood to reach an area of tissue or organ?

    <p>Collateral Circulation</p> Signup and view all the answers

    Which artery branches off the external carotid artery and supplies the upper pole of the thyroid gland?

    <p>Superior Thyroid Artery</p> Signup and view all the answers

    What is the function of tributary veins?

    <p>To collect blood from capillaries and flow into larger veins</p> Signup and view all the answers

    Which artery passes backward and lateral to the internal carotid artery as it ascends in the neck?

    <p>Occipital Artery</p> Signup and view all the answers

    Where does the right subclavian artery arise from?

    <p>Brachiocephalic/innominate artery</p> Signup and view all the answers

    Which artery is primarily responsible for supplying blood to the tongue?

    <p>Lingual Artery</p> Signup and view all the answers

    What anatomical structure can be used to palpate the pulsations of the artery close to its origin?

    <p>Sternocleidomastoid Muscle</p> Signup and view all the answers

    What is a feature of the subclavian arteries regarding their transition at the first rib?

    <p>They become the axillary artery.</p> Signup and view all the answers

    Which artery arises from the arch of the aorta?

    <p>Left Subclavian Artery</p> Signup and view all the answers

    What anatomical feature is formed between adjacent blood vessels contributing to collateral circulation?

    <p>Anastomoses</p> Signup and view all the answers

    Which area does the superior mesenteric artery NOT supply?

    <p>Superior part of the duodenum</p> Signup and view all the answers

    What is the primary function of the portal vein?

    <p>To transport nutrients from the digestive tract to the liver</p> Signup and view all the answers

    Which of the following arteries branches from the superior mesenteric artery?

    <p>Inferior pancreaticoduodenal artery</p> Signup and view all the answers

    The superior mesenteric artery is primarily responsible for supplying which part of the colon?

    <p>Transverse part of the colon</p> Signup and view all the answers

    What is the fate of blood supplied by the portal vein after it reaches the liver?

    <p>It mingles with blood from the hepatic artery</p> Signup and view all the answers

    Which of the following correctly describes the venous return from the liver?

    <p>Formed into small veins to the inferior vena cava</p> Signup and view all the answers

    What is the main role of the anastomoses with the ileocolic artery?

    <p>To provide alternate routes for blood supply</p> Signup and view all the answers

    What type of blood is primarily carried to the liver by the portal vein?

    <p>Nutrient-laden blood from the digestive system</p> Signup and view all the answers

    Which organs are involved in uniting to form the portal vein?

    <p>Stomach, spleen, pancreas, and intestines</p> Signup and view all the answers

    Which artery supplies the descending colon and sigmoid colon?

    <p>Inferior mesenteric artery</p> Signup and view all the answers

    What condition is NOT a result of high pressure in the portal vein?

    <p>Hypotension</p> Signup and view all the answers

    Which vein is associated with the short gastric veins?

    <p>Left gastric vein</p> Signup and view all the answers

    What part of the colon receives blood from the inferior mesenteric artery?

    <p>Descending colon</p> Signup and view all the answers

    Which of the following does NOT describe the function of the portal vein?

    <p>Drains the lower extremities</p> Signup and view all the answers

    Which plexus is associated with the superior hemorrhoidal vein?

    <p>Superior hemorrhoidal plexus</p> Signup and view all the answers

    The superior mesenteric artery primarily supplies which section of the gastrointestinal tract?

    <p>Ileum</p> Signup and view all the answers

    What is typically formed as a consequence of portal hypertension?

    <p>Esophageal varices</p> Signup and view all the answers

    What connects the portal vein to the inferior mesenteric artery's drainage?

    <p>Superior mesenteric artery</p> Signup and view all the answers

    Which structure is primarily involved in draining the greater part of the rectum?

    <p>Inferior mesenteric artery</p> Signup and view all the answers

    What is the primary source of the retromandibular vein?

    <p>Superficial temporal vein and maxillary vein</p> Signup and view all the answers

    Which vein is formed from the union of the posterior auricular vein and the retromandibular vein?

    <p>External jugular vein</p> Signup and view all the answers

    At which vertebral level does the descending thoracic aorta commence?

    <p>T4</p> Signup and view all the answers

    The anterior jugular vein is joined to the opposite vein by which structure?

    <p>Jugular arch</p> Signup and view all the answers

    What veins contribute to the formation of the internal jugular vein?

    <p>Sigmoid sinus and posterior auricular vein</p> Signup and view all the answers

    Which vein descends across the sternocleidomastoid muscle and drains into the subclavian vein?

    <p>External jugular vein</p> Signup and view all the answers

    What anatomical feature marks the transition of the thoracic aorta into the abdominal aorta?

    <p>Piercing of the diaphragm</p> Signup and view all the answers

    Which of the following veins is NOT a tributary of the external jugular vein?

    <p>Anterior jugular vein</p> Signup and view all the answers

    What is the primary role of the accessory hemiazygos vein?

    <p>To provide collateral venous return during IVC obstruction</p> Signup and view all the answers

    Which of the following statements about the thoracoepigastric vein is accurate?

    <p>It provides an alternative pathway between the axillary and femoral veins</p> Signup and view all the answers

    Which vertebrae does the accessory hemiazygos vein primarily descend along?

    <p>T5 to T8</p> Signup and view all the answers

    Which of the following is NOT a tributary of the thoracoepigastric vein?

    <p>Superior intercostal veins</p> Signup and view all the answers

    Where does the accessory hemiazygos vein typically join the azygos vein?

    <p>At T6 or T7 vertebrae</p> Signup and view all the answers

    What is the primary function of the vertebral artery in the context of cervical anatomy?

    <p>Join the basilar artery and contribute to the circle of Willis</p> Signup and view all the answers

    Which muscle is noted to pass anterior to the maxillary artery?

    <p>Scalenus anterior muscle</p> Signup and view all the answers

    Which of the following correctly describes the course of the maxillary artery?

    <p>Courses similarly to the subclavian artery</p> Signup and view all the answers

    Which branches does the first part of the subclavian artery not supply?

    <p>Thorax</p> Signup and view all the answers

    What is primarily supplied by the maxillary artery?

    <p>Teeth and nasal region</p> Signup and view all the answers

    Which part of the vertebral artery's course is highlighted in its anatomical description?

    <p>It ascends through cervical vertebral foramina</p> Signup and view all the answers

    Which arteries form the basilar artery?

    <p>Two vertebral arteries</p> Signup and view all the answers

    What structures besides the vertebral artery provide vascular supply to the head and neck?

    <p>Branches from the carotid artery</p> Signup and view all the answers

    Which anatomical relationship is correct regarding the vertebral artery?

    <p>It joins the contralateral vertebral artery at the medial border of scalenus anterior</p> Signup and view all the answers

    Which artery is most likely involved in supplying blood to the meninges inside the skull?

    <p>Vertebral artery</p> Signup and view all the answers

    What is the primary feature of collateral circulation?

    <p>It involves multiple pathways for blood to reach tissues.</p> Signup and view all the answers

    Which arterial branch primarily supplies the upper pole of the thyroid gland?

    <p>Superior thyroid artery</p> Signup and view all the answers

    At what point does the right subclavian artery arise?

    <p>From the brachiocephalic artery</p> Signup and view all the answers

    Which artery is NOT classified as a branch of the external carotid artery?

    <p>Internal thoracic artery</p> Signup and view all the answers

    Where does the external carotid artery primarily terminate?

    <p>In the parotid gland</p> Signup and view all the answers

    Which vessel crosses the external carotid artery as it ascends in the neck?

    <p>Posterior belly of the digastric muscle</p> Signup and view all the answers

    Which statement best describes tributary veins?

    <p>They are smaller vessels that drain into larger veins.</p> Signup and view all the answers

    What is one characteristic of the ascending pharyngeal artery?

    <p>It branches from the external carotid artery.</p> Signup and view all the answers

    Which artery arches upward and laterally over the pleura?

    <p>Right subclavian artery</p> Signup and view all the answers

    What is a significant role of scapular anastomoses?

    <p>They provide an alternative pathway for blood supply.</p> Signup and view all the answers

    What is a significant function of the azygos vein?

    <p>It provides an alternate pathway for blood to the right atrium when a vena cava is blocked.</p> Signup and view all the answers

    Where does the azygos vein primarily ascend in the body?

    <p>Ascending the posterior mediastinum on the right side.</p> Signup and view all the answers

    Which anatomical landmark is associated with the azygos vein?

    <p>Arch of the azygos vein.</p> Signup and view all the answers

    What variation may occur in the arch of the azygos vein?

    <p>It may arch laterally, forming a pleural septum.</p> Signup and view all the answers

    What is true regarding the relationship between the hemiazygos vein and the azygos vein?

    <p>The hemiazygos vein is considered a tributary to the azygos vein.</p> Signup and view all the answers

    What major structures do the azygos vein and its related veins drain?

    <p>Thoracic and abdominal walls, as well as parts of the back.</p> Signup and view all the answers

    Which veins contribute to the formation of the azygos vein?

    <p>The ascending lumbar veins and right subcostal veins.</p> Signup and view all the answers

    What is a primary anatomical position of the azygos vein?

    <p>Posterior to the inferior vena cava.</p> Signup and view all the answers

    What role do anterior intercostal arteries primarily play?

    <p>They supply oxygenated blood to the thoracic wall.</p> Signup and view all the answers

    Study Notes

    Fibrous Pericardium

    • Composed of dense fibrous irregular connective tissue
    • Anchors the heart to surrounding structures
    • Protects the heart from trauma and damage
    • Prevents the heart from overfilling with blood due to its non-distensible nature

    Endocardial Lining

    • Covers the mitral valve (bicuspid) and aortic semilunar valve
    • Present in all chambers of the heart

    Fibrous Pericardium

    • Dense fibrous irregular connective tissue
    • Anchors heart to nearby structures
    • Acts as protective barrier against trauma and damage
    • Prevents excessive blood filling by restricting expansion

    Endocardial Lining

    • Covers both mitral valve (bicuspid) and aortic semilunar valve
    • Lines all chambers of the heart

    Fibrous Pericardium

    • Composed of dense irregular connective tissue
    • Anchors the heart in the chest cavity
    • Acts as a protective barrier against external trauma
    • Limits overexpansion of the heart chambers, preventing excessive blood accumulation

    Endocardium

    • Thin layer of epithelial tissue lining the heart chambers
    • Covers the heart valves, including the mitral valve

    Heart Location and Size

    • The heart resides in the mediastinum, a specific area within the thoracic cavity.
    • Positioned approximately two-thirds to the left of the mid-sternal line.
    • Apex points towards the left hip, the base points towards the right shoulder.
    • Weighs about 200-300 grams, comparable in size to a fist.

    Heart Chambers

    • Two upper chambers: the right and left atria.
    • Right atrium receives deoxygenated blood from the inferior and superior vena cava, and the coronary sinus.
    • Left atrium receives oxygenated blood from the lungs via the pulmonary veins.
    • Valves separate the atria from the ventricles, ensuring one-way blood flow.
    • The tricuspid valve (right atrioventricular) separates the right atrium from the right ventricle.
    • The bicuspid (mitral or left atrioventricular) valve separates the left atrium from the left ventricle.

    Valvular Structure

    • Composed of three layers: zona spongiosa, zona fibrosa, and zona ventricularis.
    • These layers are covered by an endothelial lining.
    • Collagen fibers called chordae tendineae are attached to the valves, preventing backflow and keeping them taut.
    • Chordae tendineae are anchored by papillary muscles.

    Ventricles

    • The right ventricle pumps deoxygenated blood to the lungs.
    • The left ventricle is a powerful pump, sending oxygenated blood to the rest of the body.
    • Pulmonary semilunar valve separates the right ventricle from the pulmonary trunk.
    • Aortic semilunar valve separates the left ventricle from the aorta.

    Heart Septum

    • Interventricular septum separates the right and left ventricles.
    • Plays a critical role in preventing blood mixing between the ventricles.
    • An interatrial septum also separates the right and left atria.

    Great Vessels

    • The pulmonary trunk, main artery leading to the lungs, originates from the right ventricle.
    • Pulmonary trunk divides into the left pulmonary artery and the right pulmonary artery.
    • The aorta, the main artery supplying the body, originates from the left ventricle.
    • The ascending aorta curves into the aortic arch, giving rise to the brachiocephalic artery, the left common carotid artery, and the left subclavian artery.

    Layers of the Heart

    • The innermost layer, the endocardium, is composed of endothelium tissue.
    • The middle layer, the myocardium, is composed of cardiac muscle tissue. The left ventricle has a thicker myocardium than the right ventricle due to its greater pumping force.
    • The outermost layer, the epicardium (or visceral layer of the serous pericardium), forms the outer surface of the heart.
    • The pericardial cavity is a space filled with pericardial fluid, cushioning the heart and reducing friction.
    • The parietal layer of the serous pericardium lines the pericardial cavity and is continuous with the epicardium.
    • The fibrous pericardium is a tough outer sac that surrounds the heart.

    Fibrous Pericardium

    • Composed of dense fibrous irregular connective tissue.
    • Anchors the heart to surrounding structures.
    • Protects the heart from trauma and damage.
    • Prevents the heart from overfilling with blood due to its non-distensible nature.

    Endocardium

    • Covers valves such as the mitral (bicuspid) and aortic semilunar valves.

    Location and Size

    • The heart sits in the mediastinum of the thoracic cavity, slightly shifted left of the midline.
    • The apex points towards the left hip, and the base points towards the right shoulder.
    • The heart weighs approximately 200-300 grams, roughly the size of a fist.

    Heart Chambers

    • The heart is divided into four chambers: the right atrium, left atrium, right ventricle, and left ventricle.
    • The right atrium collects deoxygenated blood from the body through the superior vena cava, inferior vena cava, and coronary sinus.
    • The left atrium receives oxygenated blood from the lungs through the pulmonary veins.
    • The right ventricle pumps deoxygenated blood to the lungs through the pulmonary valve.
    • The left ventricle pumps oxygenated blood to the entire body through the aortic valve.

    Heart Valves

    • The tricuspid valve separates the right atrium from the right ventricle.
    • The bicuspid (mitral) valve separates the left atrium from the left ventricle.
    • The pulmonary semilunar valve guards the opening of the pulmonary trunk from the right ventricle.
    • The aortic semilunar valve guards the opening of the aorta from the left ventricle.

    Cardiac Conduction System

    • The heart has specialized cells called nodal cells, responsible for creating action potentials and determining the heart rhythm.
    • The sinoatrial (SA) node, located in the right atrium, is the primary pacemaker of the heart.
    • The atrioventricular (AV) node, also located in the right atrium, relays electrical signals from the atria to the ventricles.

    Layers of the Heart

    • The endocardium is the inner layer of the heart, composed of epithelial tissue and connective tissue.
    • The myocardium is the middle layer of cardiac muscle tissue.
    • The left ventricular myocardium is thicker than the right ventricular myocardium due to its role in pumping blood throughout the body.
    • The epicardium is the outer layer of the heart, synonymous with the visceral layer of the serous pericardium.
    • The pericardial cavity, a space filled with serous fluid, lies between the epicardium and the parietal layer of the serous pericardium.
    • The parietal layer of the serous pericardium lines the pericardial cavity.
    • The fibrous pericardium is the tough outer layer that encases the heart, providing protection, anchoring, and preventing overfilling.

    Important Vessels

    • The pulmonary trunk, a large vessel carrying deoxygenated blood, branches into the right and left pulmonary arteries, which convey blood to the lungs.
    • The ascending aorta carries oxygenated blood from the left ventricle to the aortic arch.
    • The aortic arch carries oxygenated blood to the head, neck, and upper limbs, branching into the brachiocephalic artery, left common carotid artery, and left subclavian artery.
    • The brachiocephalic artery further branches into the right common carotid artery and right subclavian artery.

    Additional Structures

    • Chordae tendineae, collagen cords connecting the valve flaps to papillary muscles, prevent valve prolapse into the atria.
    • Papillary muscles, projections from ventricular walls, attach to chordae tendineae, supporting valve flaps.
    • The interventricular septum separates the right and left ventricles, while the interatrial septum separates the right and left atria.
    • The fossa ovalis is a remnant of the foramen ovale, a hole present in the fetal heart.

    Fibrous Pericardium

    • Consists of dense fibrous irregular connective tissue.
    • Anchors the heart to surrounding structures.
    • Offers protection from trauma and damage.
    • Prevents overfilling of blood due to its inelastic nature.

    Endocardial Lining

    • Covers the mitral valve (bicuspid) and aortic semilunar valve.

    Heart Location and Size

    • The heart resides in the thoracic cavity within a section called the mediastinum.
    • It's positioned slightly left of the mid-sternal line, predominantly on the left side.
    • The heart's apex points towards the left hip, while the base faces the right shoulder.
    • Its weight ranges from 200 to 300 grams, about the size of a fist.

    Heart Chambers

    • The right atrium receives blood from the inferior vena cava, superior vena cava, and the coronary sinus.
    • The left atrium receives oxygenated blood from the lungs through the pulmonary veins.
    • The right ventricle pumps deoxygenated blood to the lungs via the pulmonary semilunar valve.
    • The left ventricle pumps oxygenated blood to the entire body through the aortic semilunar valve.

    Heart Valves

    • The tricuspid valve, also known as the right atrioventricular valve, is located between the right atrium and right ventricle, ensuring one-way blood flow.
    • The bicuspid valve, also called the mitral valve or left atrioventricular valve, sits between the left atrium and left ventricle.
    • The pulmonary semilunar valve is positioned between the right ventricle and the pulmonary trunk.
    • The aortic semilunar valve is between the left ventricle and the aorta.

    Heart Septa

    • The interventricular septum separates the right and left ventricles.
    • The interatrial septum separates the right and left atria.

    Major Vessels

    • The pulmonary trunk branches into the left and right pulmonary arteries, carrying deoxygenated blood to the lungs.
    • The aorta is the primary artery transporting oxygenated blood from the left ventricle to the body, including the ascending aorta and the aortic arch.
    • The brachiocephalic artery is the first branch off the aortic arch.
    • The left common carotid artery is the second branch off the aortic arch.
    • The left subclavian artery is the third branch off the aortic arch.

    Heart Layers

    • The endocardium, the innermost layer, is comprised of epithelial tissue with underlying connective tissue.
    • The myocardium, the middle layer, is made of cardiac muscle tissue responsible for the heart's contractions.
    • The epicardium, the outermost layer, is also known as the visceral layer of the serous pericardium and lines the pericardial cavity.
    • The pericardial cavity, the space between the visceral and parietal layers of the pericardium, is filled with pericardial fluid which minimizes friction during heart contractions.
    • The parietal layer of the serous pericardium is continuous with the visceral layer and lines the inside of the pericardial sac.
    • The fibrous pericardium, the outermost layer, is a tough connective tissue sac that encases the heart and aids in anchoring it.

    Other Structures

    • Chordae tendineae are collagen cords attaching to the valves, keeping them in place and preventing backflow.
    • Papillary muscles are muscles anchoring the chordae tendineae.

    Fibrous Pericardium

    • The fibrous pericardium is a dense fibrous irregular connective tissue surrounding the heart.
    • It anchors the heart to surrounding structures.
    • It offers protection against trauma and damage.
    • It prevents the heart from overfilling with blood because it's not distensible.

    Endocardium

    • The endocardium is a thin tissue layer lining the inside of the heart chambers.
    • It covers the heart's valves.

    Fibrous Pericardium

    • Composed of dense fibrous irregular connective tissue
    • Anchors the heart to surrounding structures
    • Protects the heart from trauma and damage
    • Prevents the heart from over-filling with blood due to its non-distensible nature

    Other Structures

    • The endocardium lining covers the mitral (bicuspid) valve and aortic semilunar valve

    Heart Location and Size

    • Located within the thoracic cavity, specifically in the mediastinum
    • Positioned slightly shifted to the left of the mid-sternal line, with the apex pointing towards the left hip and the base towards the right shoulder
    • Weighs approximately 200 to 300 grams, about the size of a fist

    Heart Chambers

    • Four chambers: right atrium, left atrium, right ventricle, and left ventricle
    • Right atrium receives deoxygenated blood from the body through the inferior vena cava, superior vena cava, and coronary sinus
    • Left atrium receives oxygenated blood from the lungs through the pulmonary veins

    Heart Valves

    • Ensure one-way blood flow, preventing backflow
    • Tricuspid valve separates the right atrium from the right ventricle
    • Bicuspid (mitral) valve separates the left atrium from the left ventricle
    • Pulmonary semilunar valve separates the right ventricle from the pulmonary trunk
    • Aortic semilunar valve separates the left ventricle from the aorta

    Supporting Structures

    • Chordae tendineae are collagen cords that attach to valve cusps and are anchored by papillary muscles
    • Papillary muscles are small, peg-like muscles that prevent valve prolapse
    • Interventricular septum separates the right ventricle from the left ventricle
    • Interatrial septum separates the right atrium from the left atrium

    Great Vessels

    • Pulmonary trunk carries deoxygenated blood from the right ventricle to the lungs, splitting into the left and right pulmonary arteries
    • Aorta carries oxygenated blood from the left ventricle to the body
    • Ascending aorta branches into the aortic arch, which gives rise to the brachiocephalic trunk, left common carotid artery, and left subclavian artery

    Heart Layers

    • Endocardium is the inner layer, composed of endothelial tissue and underlying connective tissue, lining the chambers
    • Myocardium is the middle layer, composed of cardiac muscle tissue, responsible for the heart's pumping action
    • Epicardium, also known as the visceral layer of the serous pericardium, is the outer layer covering the heart
    • Pericardial cavity contains pericardial fluid, which lubricates the heart and reduces friction during contraction and relaxation
    • Parietal layer of the serous pericardium lines the pericardial cavity, continuous with the epicardium
    • Fibrous pericardium is the outermost layer, a tough, fibrous sac that encloses the heart

    Fibrous Pericardium

    • Made of dense fibrous irregular connective tissue
    • Anchors the heart to surrounding structures
    • Protects the heart from trauma or damage
    • Prevents the heart from overfilling with blood because it is not distensible

    Endocardium

    • Lines all the chambers of the heart, including the ventricles, atria, and valves (mitral valve, bicuspid valve, aortic semilunar valve)

    Cardiac Cycle

    • The cardiac cycle is a series of mechanical events that involve blood flow through the heart chambers, lasting approximately 0.8 seconds on average.
    • Diastole is the relaxation phase of the heart chambers.
    • Systole is the contraction phase of the heart chambers.

    Mid to Late Ventricular Diastole (Phase 1)

    • Blood returns to the heart from the:
      • Inferior vena cava
      • Superior vena cava
      • Coronary sinus
      • Pulmonary veins
    • Rising atrial pressure opens the atrioventricular (AV) valves:
      • Tricuspid valve: Between right atrium and right ventricle
      • Bicuspid valve (Mitral valve): Between left atrium and left ventricle
    • Passive filling occurs: Approximately 70-80% of blood flows into the ventricles.
    • During this phase, atrial pressure is greater than ventricular pressure, opening the AV valves.
    • Aortic & Pulmonary pressure is greater than ventricular pressure, keeping the semilunar valves closed.
    • EKG: The P wave represents atrial depolarization, which marks the start of atrial contraction.
    • This phase is also known as the ventricular filling phase.

    Isovolumetric Contraction (Phase 2)

    • Ventricular depolarization and contraction begins.
    • Ventricular pressure starts rising but is still less than aortic and pulmonary pressure.
    • AV valves close, creating the first heart sound ("Lub" or S1).
    • Semilunar valves remain closed.
    • EKG: The QRS complex represents ventricular depolarization, which initiates ventricular contraction.

    Ventricular Ejection (Phase 3)

    • Rising ventricular pressure overcomes aortic and pulmonary pressure.
    • Semilunar valves open, allowing blood to be ejected out of the ventricles.
    • AV valves remain closed.
    • Ventricular pressure is greater than arterial pressure.
    • EKG: The QRS complex continues to represent ventricular depolarization.

    Isovolumetric Relaxation (Phase 4)

    • Ventricular relaxation and repolarization begins.
    • Semilunar valves close, creating the second heart sound ("Dub" or S2).
    • AV valves remain closed.
    • Arterial pressure is greater than ventricular pressure.
    • EKG: No specific wave or complex is associated with this phase, as ventricular relaxation occurs during the ST segment.
    • Note:* The "Dicrotic Notch" is a brief rise in aortic pressure that occurs due to the closure of the aortic semilunar valve.

    Isovolumetric Relaxation Phase

    • The ventricular pressure is still greater than the atrial pressure, and the AV valves remain closed.
    • The semilunar valves snap shut as the ventricular pressure falls below aortic pressure, producing the dub sound (S2).
    • This phase is also known as the isovolumetric relaxation phase, as the ventricles are relaxing and repolarizing, and the coronary arteries are filling with blood to supply the heart muscles with oxygen.
    • This phase corresponds to the T wave on the EKG.
    • The ventricles continue to relax, allowing the blood to be distributed to the pulmonary, systemic, and coronary circuits.
    • Once the ventricles are relaxed, the cycle restarts with the ventricles beginning to fill with blood.

    Mid to Late Ventricular Diastole

    • Blood flows into the heart from veins, filling the right atrium and left atrium.
    • Atrial pressure exceeds ventricular pressure, causing the atrioventricular (AV) valves to open.
    • Most blood passively flows into the ventricles due to gravity.
    • The P wave on an EKG represents atrial depolarization, which occurs at the end of ventricular diastole.
    • This phase is also known as ventricular filling.

    Isovolumetric Contraction

    • The ventricles contract, increasing pressure.
    • The AV valves close as ventricular pressure exceeds atrial pressure.
    • The semilunar valves remain closed because ventricular pressure is lower than arterial pressure.
    • The first heart sound ("Lub" or S1) occurs when the AV valves close.
    • This phase involves heart muscle contraction but no blood leaving the ventricles.

    Ventricular Ejection

    • Ventricular pressure surpasses arterial pressure, leading to semilunar valve opening.
    • Blood flows into the pulmonary trunk and aorta.
    • The AV valves remain closed due to higher ventricular pressure.
    • The QRS complex or QRS wave on an EKG represents ventricular depolarization and contraction.

    Ventricular Relaxation (Mid to Late Ventricular Systole)

    • Ventricles relax, decreasing pressure.
    • The semilunar valves close due to the recoil of elastic arteries and higher arterial pressure.
    • A slight rise in aortic pressure (dicrotic notch) occurs as the aortic semilunar valve snaps shut.
    • The AV valves remain closed as ventricular pressure remains higher than atrial pressure.
    • This phase is also known as the phase of ventricular ejection.

    Isovolumetric Relaxation

    • The ventricles relax and repolarize.
    • The AV valves remain closed because ventricular pressure is still greater than atrial pressure.
    • All four valves are closed during this brief moment.
    • The semilunar valves snapping shut creates the "dub" sound (S2).
    • The coronary arteries fill with blood, supplying the heart muscles with oxygen for ATP production and future contractions.
    • The T wave on an EKG represents ventricular repolarization.
    • This phase is also known as the isovolumetric relaxation phase because the ventricular volume remains constant.
    • This phase leads to the ventricles filling with blood again, continuing the cardiac cycle.

    The Cardiac Cycle

    • The entire cardiac cycle lasts approximately 0.8 seconds.
    • The cycle is continuous.

    Heart Anatomy

    • The heart is a three-layered organ:
      • Endocardium: Inner lining, composed of endothelial cells, forms heart valves.
      • Myocardium: Thick muscular layer, made up of cardiomyocytes, which contain sarcomeres, the contractile units.
      • Pericardium: Fibrous sac encasing the heart, with two layers: fibrous and serous.
    • Sarcomeres: Contain actin and myosin, whose interaction causes muscle contraction.
    • Cardiomyocytes: Connected by intercalated discs, ensuring rapid electrical signal transmission for coordinated contraction.
    • Pericardium:
      • Fibrous pericardium: Outer layer, anchors the heart.
      • Serous pericardium: Contains parietal and visceral layers, separated by the pericardial space.
      • Visceral pericardium: Adheres to the heart's surface, often called the epicardium.

    Cardiovascular System Components

    • The cardiovascular system has nine key components:
      • Heart:
        • Valves
        • Myocardium
        • Pericardium
        • Conduction system
        • Coronary arteries
      • Peripheral:
        • Arteries
        • Veins
        • Capillaries
        • Lymphatics

    Cardiovascular Pathologies

    • Heart Valves:
      • Valvular heart disease (abnormalities in valve function)
      • Endocarditis (inflammation of the endocardium)
    • Myocardium:
      • Heart failure (weakened heart muscle)
      • Myocarditis (inflammation of the myocardium)
    • Pericardium:
      • Pericardial effusion (fluid accumulation around the heart)
      • Pericarditis (inflammation of the pericardium)
    • Conduction system:
      • Arrhythmias (abnormal heart rhythms)
    • Coronary arteries:
      • Coronary artery disease (CAD), including heart attacks
    • Arteries:
      • Peripheral artery disease (PAD)
    • Veins:
      • Venous insufficiency (problems with blood flow in veins)
    • Capillaries:
      • Can be affected in sepsis
    • Lymphatics:
      • Lymphedema (swelling due to lymphatic system obstruction)

    Cardiovascular System Overview

    • Transports blood throughout the body
    • Composed of nine functional components
      • Heart: Valves, Myocardium, Pericardium, Conduction System, Coronary Arteries
      • Periphery: Arteries/Arterioles, Veins/Venules, Capillaries, Lymphatics

    Heart Anatomy

    • Three layers:
      • Endocardium: Innermost layer, lines heart valves, contains loose connective tissue and Purkinje fibers
      • Myocardium: Middle layer, responsible for heart muscle contraction
      • Pericardium: Outermost layer, a fibrous sac that encases the heart

    Cardiomyocyte Structure

    • Contains long myofibrils with repeating sarcomeres:
      • Sarcomeres: Contractile units containing actin and myosin filaments
      • Actin and Myosin: Proteins that drive myocyte contraction
    • High in mitochondria to produce ATP
    • Connected via intercalated discs for rapid electrolyte movement and electrical signal transmission

    Pericardium Layers

    • Fibrous pericardium: Tough outer layer, anchors the heart
    • Serous pericardium: Inner layer, folded into two layers with a potential space:
      • Parietal pericardium: Outer layer, fused to the fibrous pericardium
      • Visceral pericardium (epicardium): Inner layer, lies on the myocardium
      • Pericardial space: Contains fluid to facilitate frictionless heart movement

    Cardiovascular System Pathologies

    • Heart:
      • Valves: Valvular Heart Disease, Endocarditis
      • Myocardium: Heart Failure, Myocarditis
      • Pericardium: Pericardial Effusions, Pericarditis
      • Conduction System: Arrhythmias
      • Coronary Arteries: Coronary Artery Disease (Heart Disease)
    • Blood vessels:
      • Arteries/Arterioles: Peripheral Artery Disease
      • Veins/Venules: Venous Insufficiency
      • Capillaries: Potential site for sepsis manifestations
      • Lymphatics: Lymphedema (obstruction)

    Framework for Diagnosis

    • Helps categorize diagnostic possibilities within the cardiovascular system
    • Does not include congenital heart diseases, which typically involve multiple components

    Cardiovascular System Overview

    • The cardiovascular system is responsible for circulating blood throughout the body, delivering oxygen and removing waste products.
    • Deoxygenated blood travels from the heart to the lungs to pick up oxygen.
    • Oxygenated blood returns to the heart and is pumped to the rest of the body.
    • Blood carries essential nutrients for cellular respiration, including oxygen and carbon dioxide.
    • It also carries waste products, electrolytes, glucose, fatty acids, hormones, and components of the immune system.

    Heart Anatomy

    • The heart has four chambers: two atria and two ventricles, surrounded by muscular walls.
    • There are four valves: the tricuspid, pulmonary, mitral, and aortic valves.
    • Deoxygenated blood enters the right atrium from the superior and inferior vena cava.
    • It passes through the tricuspid valve into the right ventricle.
    • Deoxygenated blood is then pumped through the pulmonary valve into the pulmonary artery to the lungs.
    • Oxygenated blood returns from the lungs through the pulmonary veins into the left atrium.
    • Oxygenated blood flows through the mitral valve into the left ventricle, then is pumped through the aortic valve into the aorta.
    • The right ventricle is smaller and crescent-shaped, while the left ventricle is larger and more round.
    • The interatrial septum separates the right and left atria, while the interventricular septum separates the right and left ventricles.

    Heart Valves

    • Valves are composed of leaflets that allow blood flow in one direction.
    • Atrioventricular (AV) valves prevent backflow of blood from the ventricles into the atria.
    • The tricuspid valve (right) and mitral valve (left) both have chordae tendineae and papillary muscles.
    • Semilunar valves (pulmonary and aortic) have three cusps shaped like half-moons and lack chordae.
    • The heart's fibrous skeleton supports the valves and acts as a non-conductive barrier for electrical signals.

    Great Vessels

    • The superior and inferior vena cava carry deoxygenated blood to the right atrium.
    • The pulmonary artery carries deoxygenated blood to the lungs.
    • The aorta is the main artery of the body, branching into smaller arteries.
    • The pulmonary veins carry oxygenated blood to the left atrium.
    • The right and left atrial appendages are outpouchings that can be sites of blood clot formation.

    Coronary Arteries

    • The coronary arteries supply blood to the heart muscle.
    • The right coronary artery (RCA) supplies the right ventricle and conduction system.
    • The left main coronary artery (LMCA) branches into the left anterior descending (LAD) artery and left circumflex artery.
    • Anastomoses between the arteries provide redundant blood supply, ensuring adequate perfusion even if one artery becomes blocked.

    Cardiac Conduction System

    • The conduction system controls the timing of heart contractions.
    • The sinoatrial (SA) node is the pacemaker of the heart, generating electrical impulses.
    • The SA node is influenced by the sympathetic and parasympathetic nervous systems.
    • The atrioventricular (AV) node acts as a gatekeeper, slowing the electrical signal for ventricular filling.
    • The His bundle, bundle branches, and Purkinje fibers conduct the signal to the ventricles for synchronous contraction.

    Cardiac Cycle

    • The cardiac cycle is the sequence of events in a single heartbeat.
    • Each cycle begins with the SA node signal, triggering atrial contraction (atrial systole).
    • Atrial systole is also known as the atrial kick and helps fill the ventricles.
    • The AV node delays the signal, allowing for ventricular filling.
    • Ventricular contraction (ventricular systole) closes the AV valves and opens the semilunar valves.
    • Ventricular relaxation (ventricular diastole) closes the semilunar valves and opens the AV valves.
    • Systole is always shorter than diastole, and the relative duration changes with heart rate.

    Blood Vessels

    • Blood vessels carry blood away from the heart (arteries) and back to the heart (veins).
    • Arteries are thick-walled with elastic tissue and smooth muscle for high pressure.
    • Arterioles are smaller arteries responsible for resistance to blood flow.
    • Capillaries are microscopic vessels where gas exchange occurs.
    • Venules are smaller veins that connect to larger veins.
    • Veins are thin-walled and distensible, acting as blood reservoirs.
    • Lymphatic vessels return interstitial fluid to the bloodstream.

    Heart Structure & Function

    • Lymphatic System: The lymphatic system connects to the cardiovascular system through the thoracic duct, which empties into large veins in the chest.
    • Endocardium: Thin inner lining of the heart, composed of endothelial cells similar to blood vessels, forms the lining of heart valves.
    • Subendocardium: Loose connective tissue layer beneath the endocardium, contains Purkinje fibers responsible for electrical signal conduction.
    • Myocardium: Thick, muscular layer of the heart, primarily composed of cardiomyocytes (heart muscle cells).
    • Cardiomyocytes contain myofibrils made of sarcomeres (contractile units) containing actin and myosin filaments.
    • ATP and calcium binding to these filaments triggers muscle contraction.
    • Cardiomyocytes have high mitochondria density for ATP production.
    • Cells are connected by intercalated discs allowing for rapid electrolyte movement and electrical signal transmission.
    • Pericardium: Fibrous sac that encases the heart and great vessels.
      • Fibrous pericardium: Tough outer layer attached to diaphragm and sternum, holds the heart in place.
      • Serous pericardium: Smooth inner layer, folded into:
        • Parietal pericardium: Outer layer, fused to fibrous pericardium.
        • Visceral pericardium: Inner layer, sits on myocardium, also known as epicardium.
      • Pericardial space: Space between the two serous layers, contains fluid for frictionless heart movement.
      • Pathological Pericardial Effusion: Enlarged pericardial space due to fluid accumulation.

    Cardiovascular System Components & Conditions

    • Cardiovascular System: Includes 9 functional components:
      • Heart:
        • Valves: Affected by valvular heart disease and endocarditis.
        • Myocardium: Affected by heart failure and myocarditis.
        • Pericardium: Affected by pericardial effusions and pericarditis.
        • Conduction System: Impacted by various arrhythmias (abnormal heart rhythms).
        • Coronary Arteries: Affected by coronary artery disease (CAD), leading to heart attacks.
      • Blood Vessels:
        • Arteries (arterioles): Impacted by peripheral artery disease.
        • Veins (venules): Impacted by venous insufficiency.
        • Capillaries: Rarely the primary site of pathology, but can be affected by sepsis.
        • Lymphatics: Obstruction causes lymphedema.
      • Congenital Heart Disease: Can involve a single component (like a bicuspid aortic valve) or multiple components, potentially transcending the framework.

    Lymphatic System

    • Carries lymph fluid
    • Empties into the thoracic duct
    • Thoracic duct empties into veins in the thorax

    Heart Histology

    • Composed of three layers: endocardium, myocardium, and pericardium
    • Endocardium: inner lining of the heart
      • Composed of endothelial cells
      • Forms lining for heart valves
      • Contains Purkinje fibers
    • Myocardium: middle layer of the heart
      • Composed of cardiomyocytes
      • Contains myofibrils
        • Contain sarcomeres
        • Sarcomeres are the contractile units of the cell
        • Composed of actin and myosin filaments
      • Contains a high density of mitochondria
      • Connected by intercalated discs
      • Allows for rapid transmission of electrical signals
    • Pericardium: outer fibrous sac that encloses the heart
      • Fibrous pericardium: tethered to the diaphragm and sternum
      • Serous pericardium: smooth inner layer
        • Contains two layers:
          • Parietal pericardium: fused to the fibrous pericardium
          • Visceral pericardium: (also called epicardium) lies on the myocardium
      • Pericardial space: potential space between the two serous layers
        • Contains fluid that allows the heart to beat with low friction

    Cardiovascular System Components

    • Heart:
      • Valves: affected by valvular heart disease and endocarditis
      • Myocardium: affected by heart failure and myocarditis
      • Pericardium: affected by pericardial effusions and pericarditis
      • Conduction system: affected by arrhythmias
      • Coronary arteries: affected by coronary artery disease
    • Blood vessels:
      • Arteries and arterioles: affected by peripheral artery disease
      • Veins and venules: affected by venous insufficiency
      • Capillaries: rarely the primary site of pathology, but can be affected by sepsis
      • Lymphatics: affected by lymphedema

    Congenital Heart Disease

    • Often involves multiple components of the cardiovascular system
    • Can transcend the typical cardiovascular framework
    • Example: Bicuspid aortic valve

    Cardiovascular System Overview

    • The cardiovascular system is responsible for transporting blood throughout the body.
    • The heart pumps deoxygenated blood from the body to the lungs, where it picks up oxygen, then returns to the heart for distribution to the body.
    • Blood transports oxygen, vital for cellular respiration.
    • Blood also carries waste products like carbon dioxide, bilirubin, and lactate.
    • Additionally, blood transports essential components like electrolytes, glucose, fatty acids, and hormones.
    • An important function of the blood is transporting immune system components.

    Heart Anatomy

    • The heart consists of four chambers: two atria and two ventricles.
    • These chambers are encased in muscular walls.
    • The heart contains four valves: two atrioventricular valves (tricuspid and mitral) and two semilunar valves (pulmonary and aortic).
    • Crucial blood vessels, including the superior and inferior vena cava, pulmonary artery, aorta, and pulmonary veins, are connected to the heart.
    • The right and left atria are separated by the interatrial septum, while the right and left ventricles are separated by the interventricular septum.
    • The left ventricle is larger and has thicker walls compared to the right ventricle due to its responsibility for pumping blood at higher pressure.
    • The atrioventricular valves are connected to papillary muscles through chordae tendineae.
    • These structures prevent blood from flowing back from the ventricles into the atria.
    • The semilunar valves have a half-moon shape.
    • All valves are tricuspid, except the mitral valve.
    • Fibrous tissue within the heart acts as a skeleton and assists in regulating heart rhythm.
    • The superior and inferior vena cava bring deoxygenated blood from the body to the right atrium.
    • The pulmonary artery carries deoxygenated blood from the right ventricle to the lungs.
    • The aorta is the primary artery of the body. It branches into:
      • Ascending aorta
      • Aortic arch
      • Descending thoracic aorta
      • Abdominal aorta
    • The pulmonary veins transport oxygenated blood from the lungs to the left atrium.
    • Outpouchings called atrial appendages exist in the right and left atria, which can be susceptible to blood clot formation.
    • The coronary vessels supply blood to the heart itself.
    • The right coronary artery primarily supplies the right ventricle.
    • The left main coronary artery branches into the left anterior descending artery and left circumflex artery.
    • The coronary circulation contains anastomoses, which provide alternative blood supply pathways in case of blockage.

    Cardiac Conduction System

    • The conduction system controls the timing of heart contractions through electrical impulses.
    • Electrical impulses originate in the sinoatrial node (SA node), located in the right atrium.
    • The sympathetic and parasympathetic nervous systems regulate the impulse frequency from the SA node.
    • Electrical impulses from the SA node travel throughout the atria, triggering their contraction.
    • These impulses then reach the atrioventricular node (AV node) in the interatrial septum.
    • The AV node delays the signal, allowing the ventricles to fill with blood.
    • The AV node allows electrical impulses to travel through the His bundle to the right and left bundle branches.
    • Bundle branches terminate in the Purkinje fibers, which rapidly deliver the electrical signal to the ventricles.
    • This system facilitates rapid and simultaneous ventricular contraction.

    Cardiac Cycle

    • The cardiac cycle involves all the events occurring within the heart during a single heartbeat.
    • The cycle is initiated by an electrical impulse from the SA node.
    • Atrial contraction (atrial systole) pushes blood through the atrioventricular valves into the ventricles.
    • Ventricular contraction (ventricular systole) causes the closure of the atrioventricular valves, resulting in the first heart sound (S1).
    • Ventricular contraction propels blood through the semilunar valves.
    • Ventricular relaxation (ventricular diastole) leads to the closure of the semilunar valves, producing the second heart sound (S2).
    • During ventricular diastole, the atrioventricular valves open, allowing for passive filling of the ventricles.
    • Ventricular systole is shorter in duration compared to ventricular diastole.

    Blood Vessels

    • Blood vessels serve as conduits for blood flow.
    • The aorta carries blood away from the heart.
    • Arteries are thick-walled vessels containing elastic tissue and smooth muscle.
    • Arterioles are smaller arteries that regulate blood flow.
    • Capillaries are minuscule vessels with a single layer of endothelial cells, where gas exchange occurs between blood and tissues.
    • Venules are small veins.
    • Veins have thinner walls than arteries and lack elasticity, serving as a blood reservoir.
    • Arteries and veins are usually named based on their location or the organ they supply.
    • Lymphatic vessels return interstitial fluid to the bloodstream.
    • Lymphatic capillaries are involved in fluid drainage.

    Cardiovascular System Functions

    • Transports blood throughout the body
    • Delivers oxygen to tissues
    • Removes waste products like carbon dioxide
    • Transports nutrients like glucose and fatty acids
    • Carries hormones
    • Supports immune system function

    Heart Chambers

    • Four chambers: two atria and two ventricles
    • Atria receive blood: right atrium from body, left atrium from lungs
    • Ventricles pump blood: right ventricle to lungs, left ventricle to body

    Heart Valves

    • Four valves prevent backflow:
      • Tricuspid: Right atrium to right ventricle
      • Pulmonary: Right ventricle to pulmonary artery
      • Mitral: Left atrium to left ventricle
      • Aortic: Left ventricle to aorta

    Heart Walls

    • Atria separated by interatrial septum
    • Ventricles separated by interventricular septum
    • Left ventricle larger and thicker due to higher pressure output

    Heart Skeleton

    • Fibrous tissue for structural support
    • Insulates electrical signals

    Heart Conduction System

    • Coordinates muscle contractions
    • Sinoatrial (SA) node: pacemaker, generates electrical impulses (50-90 bpm)
    • Autonomic nervous system influences SA node:
      • Sympathetic: Increases heart rate
      • Parasympathetic: Decreases heart rate
    • Electrical signal travels through:
      • Atria for contraction
      • Atrioventricular (AV) node: delays signal for ventricular filling
      • His bundle: divides into right and left branches, conducts signal to ventricles
      • Purkinje fibers: rapid signal transmission in ventricles

    Heart Blood Supply (Coronary Circulation)

    • Coronary arteries supply blood to the heart
    • Right coronary artery (RCA): supplies right ventricle, influences SA and AV node function
    • Left main coronary artery branches into:
      • Left anterior descending (LAD): supplies anterior septum and anterior left ventricle
      • Left circumflex: supplies lateral left ventricle
    • Anastomoses provide redundancy in blood supply

    Cardiac Cycle

    • Sequence of events in a single heartbeat
    • Initiated by SA node's electrical impulse
    • Atrial systole (contraction): ejects blood into ventricles
    • Ventricular systole (contraction): closes AV valves, creates S1 heart sound, ejects blood
    • Ventricular diastole (relaxation): closes semilunar valves, creates S2 sound, allows passive blood flow
    • Cycle repeats continuously, generating rhythmic heartbeat

    Blood Vessels

    • Form the network for blood flow
    • Types:
      • Arteries: carry blood away from heart
      • Arterioles: regulate blood flow
      • Capillaries: gas, nutrient, and waste exchange
      • Venules: merge to form veins
      • Veins: return blood to heart

    Lymphatic System

    • Network of vessels returning interstitial fluid to bloodstream
    • Lymphatic capillaries collect fluid, transport it through larger vessels
    • Plays a role in immune function

    Cardiovascular System Components

    • Heart:
      • Valves
      • Myocardium (heart muscle)
      • Pericardium (protective sac)
      • Conduction system
      • Coronary arteries
    • Peripheral:
      • Arteries
      • Veins
      • Capillaries
      • Lymphatics

    Heart Histology Layers

    • Endocardium: Inner lining, composed of endothelial cells
      • Subendocardium: loose connective tissue, contains Purkinje fibers
    • Myocardium: Heart muscle, composed of cardiomyocytes
      • Cardiomyocytes: contain myofibrils with sarcomeres, responsible for contraction
        • Sarcomeres: contain actin and myosin filaments
      • Rich in mitochondria for energy production
      • Intercalated discs connect cardiomyocytes for rapid electrical signal transmission
    • Pericardium: Fibroserous structure encasing heart and great vessels
      • Fibrous pericardium: tough outer layer, tethered to diaphragm and sternum
      • Serous pericardium: inner layer, folded into two layers with a potential space between:
        • Parietal pericardium: outer serous layer, fused to fibrous pericardium
        • Visceral pericardium: inner serous layer, lies on myocardium, also called epicardium
        • Pericardial space: potential space between serous layers, contains fluid for frictionless movement

    Cardiovascular Pathologies

    • Heart:
      • Valvular Heart Disease: Affects heart valves
      • Endocarditis: Infection of endocardium
      • Heart Failure: Affects myocardium
      • Myocarditis: Inflammation of myocardium
      • Pericardial Effusions: Fluid buildup within pericardium
      • Pericarditis: Inflammation of pericardium
      • Arrhythmias: Abnormal heart rhythms, affecting conduction system
      • Coronary Artery Disease: Affects coronary arteries, leading to heart attacks
    • Peripheral:
      • Peripheral Artery Disease: Affects arteries and arterioles
      • Venous Insufficiency: Affects veins and venules
      • Sepsis: Can manifest in capillaries
      • Lymphedema: Obstruction of lymphatics

    Cardiovascular System Framework

    • Categorizes diagnostic possibilities
    • Congenital heart disease can affect one or multiple components

    Cardiovascular System Overview

    • The cardiovascular system includes the heart and peripheral components.
    • The heart contains five functional parts: valves, myocardium, pericardium, conduction system, and coronary arteries.
    • The peripheral system includes arteries, veins, capillaries, and lymphatics.

    Heart Structure

    • The heart has four layers: endocardium, subendocardium, myocardium, and pericardium.
    • The endocardium is the innermost layer and lines the heart valves.
    • The subendocardium lies beneath the endocardium and contains Purkinje fibers.
    • The myocardium is the thickest layer and is composed of cardiomyocytes.
    • Cardiomyocytes contain myofibrils with sarcomeres, which are the contractile units containing actin and myosin filaments.
    • Intercalated discs connect cardiomyocytes, allowing for rapid electrical signal transmission for coordinated contraction.
    • The pericardium is a fibrous sac encasing the heart, divided into fibrous and serous layers.
    • The fibrous pericardium is the outer layer, attached to the diaphragm and sternum, anchoring the heart.
    • The serous pericardium is the inner layer, with parietal and visceral layers separated by the pericardial space filled with fluid.
    • The parietal pericardium is the outer serous layer, fused to the fibrous pericardium.
    • The visceral pericardium is the inner serous layer, covering the myocardium, and is also called the epicardium.

    Cardiovascular Diseases

    • Heart diseases can affect different parts of the heart:
      • Valvular heart disease: Affects heart valves.
      • Endocarditis: Infection of heart valves.
      • Heart failure: Affects the myocardium.
      • Myocarditis: Inflammation of the myocardium.
      • Pericardial effusions: Fluid accumulation in the pericardial space.
      • Pericarditis: Inflammation of the pericardium.
      • Arrhythmias: Abnormal heart rhythms, affecting the conduction system.
      • Coronary artery disease: Affects coronary arteries, leading to heart attacks.
    • Peripheral diseases affect different parts of the peripheral system:
      • Peripheral artery disease: Affects arteries.
      • Venous insufficiency: Affects veins.
      • Sepsis: Can manifest in capillaries.
      • Lymphedema: Obstruction of lymphatics.

    Congenital Heart Disease

    • Congenital heart disease can impact one or multiple functional components.
    • It can extend beyond the nine-component framework of the cardiovascular system.

    Types of Blood Vessels

    • Elastic Conducting Arteries: Large diameter vessels like the aorta, responsible for carrying blood away from the heart. These vessels have a thick elastic layer that allows them to stretch and recoil with the pulsatile pressure of blood flow.
    • Muscular Distributing Arteries: Medium-sized arteries that deliver blood to specific organs. These arteries have a thicker layer of smooth muscle, giving them the ability to regulate blood flow to individual organs.
    • Arterioles: The smallest arteries, responsible for delivering blood to capillary beds. Arterioles have a smooth muscle layer (pre-capillary sphincters) that can constrict to regulate blood flow into capillaries.
    • Capillaries: Microscopic blood vessels where gas exchange (oxygen, carbon dioxide), nutrient delivery, and waste removal occur. Capillaries have thin walls composed of endothelial cells, allowing for easy diffusion.
    • Venules: Small veins that collect blood from capillary beds.

    Characteristics of Veins

    • Low Pressure Systems: Veins carry blood back to the heart, experiencing much lower pressure compared to arteries.
    • Capacitance Vessels or Blood Reservoirs: Veins hold a large portion of the body's blood volume, acting as reservoirs.
    • Thin Tunica Media: Veins have a thinner layer of smooth muscle compared to arteries.
    • Adaptations for Blood Return: Veins have special adaptations to ensure efficient blood return to the heart:
      • Valves: Prevent backflow of blood.
      • Muscular Milking: Contraction of skeletal muscles around veins helps propel blood upwards.
      • Respiratory Pump: Changes in thoracic cavity pressure during breathing assist in blood return.
      • Sympathetic Tone: Sympathetic nervous system innervation can constrict veins, aiding blood return.
    • Varicose Veins: Result from incompetent valves in veins, leading to blood pooling and vein dilation. Most common in the legs.
    • Varicocele: Varicose veins in the testes, more common on the left side due to the gonadal vein's anatomical route.
    • Hemorrhoids: Varicose veins in the anus, commonly caused by straining during bowel movements.

    Elastic Conducting Arteries

    • Large arteries like the aorta, brachiocephalic artery, and its branches
    • High-pressure systems designed to stretch and recoil under systolic pressure
    • Diameter ranges between 1 to 1.5 centimeters

    Muscular Distributing Arteries

    • Arteries supplying blood to specific organs
    • High-pressure systems with thick tunica media
    • Diameter around 6 millimeters

    Arterioles

    • Small vessels feeding capillary beds
    • Diameter around 35 micrometers
    • Contain pre-capillary sphincters, smooth muscle layers that control blood flow resistance
    • High resistance vessels, contributing significantly to blood flow resistance

    Capillaries

    • Smallest vessels, diameter around 8 to 10 micrometers
    • Exchange vessels for gases, nutrients, hormones, and waste products -Consist of a tunica interna, a thin basement membrane, and sometimes pericytes

    Venules

    • Small vessels draining capillary beds
    • Diameter around 20 micrometers

    Veins

    • Larger vessels with diameters averaging 5 millimeters
    • Low-pressure systems (around 5-10 mmHg)
    • Capacitance vessels, holding about 70% of the body's total blood volume
    • Thin tunica media
    • Larger lumen
    • Adaptations for low-pressure blood return:
      • Valves: Internal folds of the tunica intima preventing backflow of blood
      • Muscular Milking: Contraction of skeletal muscles surrounding veins pushes blood upwards
      • Respiratory Pump: Changes in thoracic cavity volume during breathing influence blood flow in lower veins
      • Sympathetic Tone: Sympathetic nervous system innervation can constrict vein smooth muscle, aiding blood return

    Varicose Veins

    • Occur when vein valves become incompetent and leaky, allowing blood to pool in the lower extremities
    • Cause vein dilation and tortuosity
    • Occur in the calves (varicose veins), testes (varicose veins), and anus (hemorrhoids)
    • Often associated with prolonged standing or straining

    Varicocele

    • Varicose veins in the testes, particularly common in the left testicle due to the left gonadal vein's route
    • Can lead to infertility, inflammation, and testicular swelling

    Respiratory System

    • The respiratory system is primarily responsible for oxygen intake and carbon dioxide expulsion, vital for delivering oxygen to all body parts.
    • It consists of airways, lungs, and respiratory muscles.

    Respiration

    • Respiration is the essential process of gas exchange between the environment and an organism's cells, achieved through inhalation and exhalation.
    • Inhalation is driven by the diaphragm and external intercostal muscles, with oxygen entering via the mouth and nose.
    • The oxygen passes through the larynx, trachea, bronchi, and bronchial tubes, ending in tiny air sacs called alveoli within the lungs.
    • Carbon dioxide released from blood in the capillaries is exhaled through the same pathway.

    Lungs

    • The lungs, located in the chest cavity, are the primary organs of the respiratory system.
    • Gas exchange occurs within the alveoli, millions of tiny air sacs surrounded by capillaries.
    • Lung tissue is spongy and elastic, allowing for expansion and contraction during breathing.

    Trachea

    • The trachea, or windpipe, is a tube connecting the larynx to the bronchi, serving as the main passageway for air to and from the lungs.

    Bronchi

    • The two bronchi, left and right, branch from the trachea, leading to the respective lungs.
    • They further divide into smaller bronchial tubes, with no gas exchange occurring in this section.
    • Bronchioles, the tiniest bronchial tubes, are crucial for air distribution within the lungs.

    Diaphragm

    • The diaphragm is a muscle separating the abdominal and thoracic cavities, playing a vital role in breathing.
    • It contracts during inhalation, pulling air into the lungs, and relaxes during exhalation, expelling carbon dioxide.
    • The diaphragm also assists in non-respiratory functions like expelling waste and preventing acid reflux.

    Respiratory System

    • The respiratory system brings oxygen into the body and expels carbon dioxide.
    • This process is achieved through breathing, also known as respiration.
    • The respiratory system consists of the airways, lungs, and respiratory muscles.

    Respiration

    • Respiration involves the exchange of gases between the external environment and an organism's cells.
    • Inhalation is initiated by the diaphragm and assisted by external intercostal muscles.
    • Oxygen enters the respiratory system through the mouth and nose, passing through the larynx, trachea, bronchi, bronchial tubes, and alveoli.
    • Alveoli are tiny air sacs in the lungs where gas exchange occurs.
    • The average adult has approximately 600 million alveoli.
    • Oxygen diffuses from the alveoli into the capillaries and into the arterial blood.
    • Carbon dioxide from the veins diffuses into the alveoli and is exhaled.

    Lungs

    • The lungs are the primary organs of the respiratory system, located in the chest cavity.
    • They transport oxygen from the atmosphere into the bloodstream and release carbon dioxide from the bloodstream into the atmosphere.
    • Lungs also help regulate the pH of the blood.
    • The lungs are composed of spongy, elastic tissue that stretches and contracts during respiration.

    Trachea

    • The trachea, also known as the windpipe, is a tube that extends from the larynx to the bronchi, serving as the principal passageway for air to and from the lungs.

    Bronchi

    • Bronchi are two large tubes at the bottom of the trachea, leading to the left and right lungs.
    • Each bronchus branches into smaller bronchial tubes.
    • Bronchioles are the tiniest bronchial tubes, with an average thickness similar to a human hair.
    • No gas exchange takes place in the bronchi or bronchial tubes.

    Diaphragm

    • The diaphragm is a musculomembranous partition separating the thoracic and abdominal cavities.
    • It is the primary muscle involved in inhalation.
    • Contraction of the diaphragm pulls air into the lungs, while relaxation pushes carbon dioxide out.
    • Exhalation is primarily passive, but during forced exhalation, expiratory muscles like the abdominal muscles and internal intercostal muscles are involved.
    • The diaphragm also plays a role in non-respiratory functions like expelling vomit, feces, and urine, and preventing acid reflux.

    Arteries

    • Arteries carry blood away from the heart.
    • Arteries have a thicker tunica media.
    • Arteries have a round lumen.
    • Arteries lack clotted blood in a cadaver.

    Veins

    • Veins carry blood towards the heart.
    • Veins have a thicker tunica adventitia.
    • Veins have a collapsed lumen.
    • Veins have clotted blood in a cadavers.

    Points of Palpations

    • Pulse can be palpated and counted at specific areas of the body.

    Classification of Arteries

    • Large arteries are aorta, brachiocephalic, common carotid, subclavian, and common iliac arteries.
    • Medium-sized arteries have less elastic tissue than large arteries.
    • Small-sized arteries have a muscular media with up to 8-10 layers of smooth muscle cells.

    End Artery

    • An end artery is the sole source of oxygenated blood to a portion of tissue.
    • End arteries do not anastomose (form connections).
    • Examples include arteries in the brain, retina, and kidneys.

    Blood vessels of the head and neck

    • External carotid artery is a terminal branch of the common carotid artery.
    • Parietal branches supply the posterior wall of the thorax and diaphragm.
    • Subclavian artery branches supply the thorax.
    • Internal mammary artery gives rise to the anterior intercostal arteries and superior epigastric and musculophrenic arteries.
    • Costocervical artery gives off the upper two posterior intercostal arteries.
    • Vertebral artery supplies the deep neck, cervical spinal cord, and hindbrain.

    Veins of the Thorax

    • Azygos venous system drains into the superior vena cava.

    Superficial Veins of the Upper Extremity

    • Cephalic vein ascends on the lateral side of the biceps and drains into the axillary vein.
    • Basilic vein ascends on the medial side of the biceps and joins with venae comitantes of the brachial artery to form the axillary vein.
    • Median cubital vein connects the cephalic and basilic veins and is located in the cubital fossa.

    Palmar Arterial Anastomosis

    • The arterial supply of the hand is derived from two anastomotic arches (superficial and deep).
    • The arches are formed by the anastomosis between radial, ulnar, and their branches in the palm.

    Axillary Artery

    • It conveys oxygenated blood to the lateral aspect of the thorax, axilla, and upper limb.
    • It begins at the lateral border of the 1st rib and ends in the lower border of teres major.
    • It is known as the subclavian artery before the 1st rib and brachial artery after the teres major.
    • It has three parts: first part, second part, and third part.
    • It branches into the superior thoracic artery, which supplies the first two intercostals.

    Brachial Artery

    • It is the continuation of the axillary artery beyond the lower margin of the teres major muscle.
    • It runs down the ventral surface of the arm until it reaches the cubital fossa at the elbow.
    • It divides into the radial and ulnar arteries.
    • Its branches include profunda brachii artery, superior ulnar collateral artery, inferior ulnar collateral artery, radial artery, ulnar artery, and nutrient branches to the humerus.

    Subclavian Vein

    • Continuation of the axillary vein
    • Joins the internal jugular vein to form the brachiocephalic vein
    • Receives the external jugular vein
    • Often receives the thoracic duct on the left side and the right lymphatic duct on the right

    Relations of the Subclavian Vein

    • Anteriorly: clavicle
    • Posteriorly: scalenus anterior muscle and the phrenic nerve
    • Inferiorly: The upper surface of the first rib

    Branches of the Thoracic Aorta

    • Visceral branches
      • Pericardial branches
      • Bronchial branches – supplies trachea, bronchi and lungs
      • Mediastinal branches- supplies lymph nodes in the posterior mediastinum
      • Esophageal artery – supplies middle third of esophagus
    • Parietal branches
      • Superior phrenic arteries - Immediately inferior to the aortic hiatus
      • Inferior phrenic arteries - Usually four pairs
      • Lumbar arteries - Posterior abdominal wall and spinal cord
      • Median sacral arteries - Superior to the aortic bifurcation, pass inferiorly across lumbar vertebrae, sacrum and coccyx
      • Common iliac arteries - Bifurcation usually occurs at the level of L4 vertebra

    General Features of Vessel Walls

    • Blood vessels, irrespective of size, and with the exception of capillaries and venules, have 3 concentric layers (tunicae)
      • Intima (tunica intima) - innermost layer, main component, the endothelium, lines the entire vascular tree
      • Media (tunica media) - made of muscle tissue, elastic fibers and collagen, thickest layer in arteries, the media is absent in capillaries and is comparatively thin in veins
      • Adventitia (tunica adventitia) - outer coat of the vessel, and consists of connective tissue, nerves and vessel capillaries

    Arteries vs Veins

    • Arteries
      • Deeply located
      • Thicker walls
      • Light Colored
      • Carries oxygenated blood (except pulmonary arteries)
    • Veins
      • Superficially located
      • Thinner walls
      • Collapsed
      • Carries deoxygenated blood (except pulmonary veins)

    Systemic Circulation

    • Part of the cardiovascular system which carries oxygenated blood away from the heart to the body, and returns deoxygenated blood back to the heart
    • Physiologic theory of circulation was first described by William Harvey
    • Main trunks belonging to the systemic circulation
      • Celiac trunk
      • Superior mesenteric artery
      • Inferior mesenteric artery
      • Common liacs

    Pulmonary Circulation

    • portion of the cardiovascular system which carries oxygen-depleted blood away from the heart, to the lungs, and returns oxygenated blood back to the heart
    • First proposed by Ibn al-Nafis, an Arab physician

    Blood Flow of Pulmonary Circulation

    • Superior and inferior vena cava  RA  tricuspid valve  RV  semilunar valve  pulmonary artery/trunk  lungs  pulmonary capillaries  pulmonary vein  LA  mitral valve  LV  aortic valve  aorta  systemic circulation

    Portal Circulation

    • The pathway of blood flow from the GI tract and spleen to the liver via the portal vein and its tributaries
    • System of veins comprising the hepatic portal vein and its tributaries

    Azygos Vein

    • Will serve as an alternate pathway if ever the superior vena cava (or inferior) is blocked
    • Lies on the right side
    • Posterior aspect of the inferior vena cava
    • Below the level of the renal veins
    • Origin is not constant
    • Vein running up the right side of the thoracic vertebral column
    • It can provide an alternate path for blood to the right atrium by allowing the blood to flow between the venae cavae when one vena cava is blocked
    • Formed by the union of the ascending lumbar veins with the right subcostal veins at the level of the 12th thoracic vertebra, ascending in the posterior mediastinum
    • Arching over the right main bronchus posteriorly at the root of the right lung to join the superior vena cava
    • "arch of the azygos vein" (arcus venae azygos) is an important anatomic landmark
    • As a rare anatomical variation, the arch can be displaced laterally, thereby creating a pleural septum separating an azygos lobe from the upper lobe of the right lung
    • The azygos vein is unpaired in that there is only one in the body, mostly on the right side
    • While there is the hemiazygos vein and its accessory on the left side of the body, they are considered tributaries of the azygos vein rather than its left-side equivalent
    • These veins drain the back, thoracic and abdominal walls to provide another means of venous drainage from the abdomen and thorax

    Splenic Artery

    • The splenic artery is the largest branch of the celiac artery. It is remarkable for the tortuosity of its course
    • On arriving near the spleen, it divides into branches: some enter the hilus of that organ between the two layers of the phrenicolienal ligament to be distributed to the tissues of the spleen; some are given to the pancreas; others pass to the greater curvature of the stomach between layers of the gastrolienal ligament.
    • Branches:
      • Pancreatic
      • Short Gastric
      • Left Gastroepiploic

    Small Saphenous Vein

    • From its origin, it courses around the lateral aspect of the foot (inferior and posterior to the lateral malleolus)
    • Runs along the posterior aspect of the leg (with the sural nerve)
    • Passes between the heads of the gastrocnemius muscle
    • Drains into the popliteal vein, approximately at or above the level of the knee joint.

    Great Saphenous Vein

    • Originates from where the dorsal vein of the first digit (the large toe) merges with the dorsal venous arch of the foot
    • After passing anterior to the medial malleolus (where it often can be visualized and palpated), it runs up the medial side of the leg.
    • At the knee, it runs over the posterior border of the medial epicondyle of the femur bone.

    Relations of Great Saphenous Vein

    • Front (from above downward)
      • Popliteal surface of the femur
      • The back of the knee-joint
      • Fascia covering the Popliteus
    • Back (covered by)
      • Semimembranosus (above)
      • Gastrocnemius and Plantaris (below)

    Anterior Tibial Artery

    • Terminal branch of the popliteal artery
    • Arises at the distal border of popliteus
    • At first in the flexor compartment, it passes between the heads of tibialis posterior and through the oval aperture in the proximal part of the interosseous membrane to reach the extensor region.

    Internal Thoracic Artery

    • Runs caudally behind the anterior chest wall, anterior to the ribs
    • Gives off anterior intercostal branches and perforating vessels to the breast
    • Terminates in the superior epigastric artery and the musculophrenic artery

    Thyrocervical Trunk

    • Very short, thick arterial trunk that divides into three branches:
      • Inferior Thyroid Artery
      • Suprascapular Artery
      • Deep Circumflex Iliac Artery
    • Supplies the lower neck, posterior shoulder, and thyroid gland

    Thoracoepigastric Vein

    • Ascends on the left side of the vertebral column, posterior to the thoracic aorta
    • Crosses to the right, posterior to the aorta, thoracic duct, and esophagus to join the azygos vein
    • Receives the inferior three intercostal veins, inferior esophageal veins, and several small mediastinal branches
    • Alternate pathway to connect axillary and femoral veins
    • Important venous connection between the lateral thoracic vein and the superficial epigastric vein

    Accessory Hemiazygos Vein

    • Begins at the medial end of the 4th or 5th intercostal space
    • Descends on the left side of the vertebral column from T5 to T8
    • Receives tributaries from veins in the 4th to 8th intercostal spaces
    • Crosses over T7 or T8 vertebrae, posterior to the thoracic aorta and thoracic duct, where it joins the azygos vein
    • Sometimes joins the hemiazygos vein and opens with it in the azygos

    Tributaries of the Portal Vein

    • Splenic vein
    • Inferior mesenteric vein
    • Superior mesenteric vein
    • Left gastric vein
    • Right gastric vein
    • Cystic veins

    Porto-Caval Anastomosis

    • Anastomosis between veins of portal circulation and those of systemic circulation
    • Normal conditions: portal venous blood traverses the liver and drains into the inferior vena cava
    • If the direct route is blocked other smaller communications exist between the portal and systemic systems
    • Important in portal hypertension

    Areas of Porto-Caval Anastomoses

    • Lower third of the esophagus, the esophageal branches of the left gastric vein (portal tributary) anastomose with the esophageal veins draining the middle third of the esophagus into the azygos veins (systemic tributary)
    • Halfway down the anal canal, the superior rectal veins (portal tributary) draining the upper half of the anal canal anastomose with the middle and inferior rectal veins (systemic tributaries) which are tributaries of the internal iliac and internal pudendal veins, respectively.
    • Paraumbilical veins connect to the left branch of the portal vein with the superficial veins of the anterior abdominal wall (systemic tributaries)
    • Veins of the ascending colon, descending colon, duodenum, pancreas, and liver (portal tributary) anastomose with the renal, lumbar, and phrenic veins (systemic tributaries)

    Importance of Porto-Caval Anastomosis

    • Portal hypertension – hypertension in the portal vein and its tributaries
    • Causes blood being forced down alternate channels by the increased resistance to flow through the portal system
    • Enlargement of the portal-systemic connections is frequently accompanied by congestive enlargement of the spleen

    Upper Extremity Blood Vessels

    • Scapular Arterial Anastomosis
      • System connecting each subclavian artery and the corresponding axillary artery, forming an anastomosis around the scapula
      • Allows for blood to flow past the joint regardless of the position of the arm
    • Blood Vessels involved:
      • Transverse Cervical Artery
      • Transverse Scapular Artery
      • Branches of Subscapular Artery
      • Branches of Thoracic Aorta
    • The first part of the subclavian with the third part of the axillary, providing a collateral circulation
    • Allows for blood to continue circulating if the subclavian is obstructed

    Popliteal Artery

    • Extension of the "superficial" femoral artery after passing through the adductor canal and adductor hiatus above the knee
    • Terminates in its bifurcation into the anterior tibial artery and posterior tibial artery
    • Supplies the knee joint and muscles in the thigh and calf
    • Branches:
      • Anterior Tibial Artery
      • Posterior Tibial Artery
      • Sural Artery
      • Superior Genicular Artery
      • Lateral Superior Genicular Artery
      • Middle Genicular Artery
      • Lateral Inferior Genicular Artery
      • Medial Inferior Genicular Artery

    Dorsalis Pedis

    • Dorsal artery of the foot
    • Continuation of the anterior tibial artery distal to the ankle
    • Passes to the proximal end of the first intermetatarsal space, where it turns into the sole between the heads of the first dorsal interosseous to complete the plantar arch
    • Superficial in position and is crossed by the inferior extensor retinaculum and the first tendon of the extensor digitorum brevis
    • Pulsations are easily palpated

    Superficial Veins of the Lower Extremity

    • Thoracoepigastric Vein
      • Branches:
        • Subscapular - divides into thoracodorsal and circumflex scapular branches.
        • Anterior humeral circumflex - Passes around surgical neck of humerus.
        • Posterior humeral circumflex - Runs with axillary nerve through the quadrangular space to anastomose with anterior circumflex branch.
          • The anterior and posterior circumflex will meet at the surgical neck of the humerus.

    Thoracic Aorta

    • Starts at the vertebral level T4.
    • Ends as the abdominal aorta at vertebral level T12.
    • Continuation of the arch of the aorta.

    Descending Thoracic Aorta

    • Terminates as the abdominal aorta.
    • The abdominal aorta pierces the diaphragm.

    Maxillary Vein

    • Formed in the infratemporal fossa from the pterygoid venous plexus.
    • Joins the superficial temporal vein to form the retromandibular vein

    Retromandibular Vein

    • Formed by the union of the superficial temporal and maxillary veins.
    • On leaving the parotid salivary gland, it divides into an anterior branch, which joins the facial vein, and a posterior branch, which joins the posterior auricular vein to form the external jugular vein.

    External Jugular Vein

    • Formed behind the angle of the jaw by the union of the posterior auricular vein with the posterior division of the retromandibular vein.
    • Descends across the sternocleidomastoid muscle and beneath the platysma muscle.
    • Drains into the subclavian vein behind the middle of the clavicle.

    Tributaries of External Jugular Vein

    • Posterior external jugular vein from the back of the scalp.
    • Transverse cervical vein from the skin and the fascia over the posterior triangle.
    • Suprascapular vein from the back of the scapula.

    Anterior Jugular Vein

    • Descends in the front of the neck close to the midline.
    • Just above the sternum, it is joined to the opposite vein by the jugular arch.
    • Joins the external jugular vein deep to the sternocleidomastoid muscle.

    Internal Jugular Vein

    • Large vein that receives blood from the brain, face, and neck.
    • Starts as a continuation of the sigmoid sinus and leaves the skull through the jugular foramen.

    Abdominal Aorta

    • Begins at the level of the diaphragm, crossing it via the aortic hiatus at vertebral level of T12.
    • Travels down the posterior wall of the abdomen, anterior to the vertebral column.
    • Follows the curvature of the lumbar vertebrae; convex anteriorly.
    • The peak of this convexity is at the level of the fourth lumbar vertebra (L4).

    Branches of Abdominal Aorta

    • Visceral branches supply organs.
    • Posterior/ Parietal branches supply the diaphragm or body wall.
    • Terminal branches.

    A. Visceral Branches

    • Paired branches include middle suprarenals, renals, internal spermatics, and ovarian arteries.
    • Unpaired Branches include celiac, superior mesenteric, and inferior mesenteric arteries.

    B. Posterior/Parietal Branches

    • Lumbar arteries.

    Left Gastric Artery

    • Branches to the esophagus.
    • Smallest of the 3 branches of the celiac artery.
    • Passes upward and to the left, posterior to the omental bursa to the cardiac orifice of the stomach.
    • Anastomose with the aortic esophageal arteries.
    • Supply the cardiac part of the stomach, anastomosing with branches of the lienal artery.
    • Gives branches to both surfaces of the stomach and anastomoses with the right gastric artery.

    Hepatic Artery

    • Intermediate in size between left gastric and lienal arteries (adults).
    • Largest of the 3 branches of the celiac artery (fetus).
    • Includes right gastric, gastroduodenal, right gastroepiploic, superior pancreaticoduodenal, and cystic arteries.

    Azygos Vein

    • Serves as an alternate pathway if ever the superior vena cava (or inferior) is blocked.
    • Lies on the right side.
    • Posterior aspect of the inferior vena cava.
    • Below the level of the renal veins.
    • Origin is not constant.
    • Vein running up the right side of the thoracic vertebral column.
    • Can provide an alternate path for blood to the right atrium by allowing the blood to flow between the venae cavae when one vena cava is blocked.
    • Formed by the union of the ascending lumbar veins with the right subcostal veins at the level of the 12th thoracic vertebra, ascending in the posterior mediastinum.
    • Arching over the right main bronchus posteriorly at the root of the right lung to join the superior vena cava.
    • "Arch of the azygos vein" (arcus venae azygos) is an important anatomic landmark.
    • The arch can be displaced laterally, creating a pleural septum separating an azygos lobe from the upper lobe of the right lung.
    • The azygos vein is unpaired.
    • While there is the hemiazygos vein and its accessory on the left side of the body, they are considered tributaries of the azygos vein rather than its left-side equivalent.
    • These 3 will drain the back, thoracic and abdominal walls.
    • The accessory azygos vein is frequently connected to the superior intercostal vein.

    Arteries that Supply the External Surface of the Anterior Thoracic Wall

    • Internal thoracic artery.
    • Gives rise to two anterior intercostal arteries in each of the upper six intercostal spaces and terminates at the sixth intercostal space by dividing into the musculophrenic and superior epigastric arteries.

    Anterior Intercostal Arteries

    • Are 12 small arteries, 2 in each of the upper six intercostal spaces that run laterally, 1 each at the upper and lower borders of each space.

    Hardening and swelling of veins under the skin of the breast and front chest wall

    • Caused by a blood clot.

    Popliteal Artery

    • Becomes the popliteal artery as it passes through an opening in adductor magnus near the junction of the middle and distal thirds of the thigh.

    Branches of Popliteal Artery

    • Superficial and deep external pudendal arteries.
    • Superficial epigastric artery.
    • Superficial circumflex iliac artery.
    • Profunda femoris artery.
    • Descending genicular (saphenous) arteries.

    Posterior Tibial Artery

    • Descends medially in the flexor compartment and divides under abductor hallucis.
    • Posterior to tibialis posterior, flexor digitorum longus, the tibia, and the ankle joint.

    Terminal Branches of Posterior Tibial Artery

    • Circumflex fibular artery.
    • Fibular artery.
    • Medial plantar artery.

    Transverse Cervical Artery

    • Also called the cervicodorsal trunk.
    • Splits into superior intercostal artery supplying the first and second intercostal spaces and deep cervical artery supplying the deep muscles of the neck
    • Supplies muscles of the neck posteriorly such as the first two posterior intercostal spaces.

    Internal Carotid Artery

    • Begins at the bifurcation of the common carotid artery at the level of the upper border of the thyroid.
    • Supplies the brain, the eye, the forehead, and part of the nose.
    • Ascends in the neck embedded in the carotid sheath with the internal jugular vein and vagus nerve.
    • Lies superficially at first, then passes deep to the parotid salivary gland.
    • Leaves the neck by passing into the cranial cavity through the carotid canal in the petrous part of the temporal bone.
    • Passes upward and forward in the cavernous venous sinus (without communicating with it).
    • Leaves the sinus and passes upward again medial to the anterior clinoid process of the sphenoid bone.

    Collateral Circulation

    • Secondary or accessory circulation occurs when an area of tissue or an organ has a number of different pathways for blood to reach it.
    • Often the result of anastomoses - branches formed between adjacent blood vessels.
    • E.g., scapular anastomoses.

    Tributary Vein

    • A vessel that feeds or flows into or joins a larger vessel.

    Branches of the External Carotid Artery

    • Superior thyroid artery - supplies the upper pole thyroid gland
    • Ascending pharyngeal artery – supplies the pharyngeal wall
    • Lingual artery – supplies the tongue
    • Facial artery - supplies the tonsils, submandibular gland, and face.
    • Occipital artery - supplies the back of the scalp
    • Posterior auricular artery - supplies the auricle and scalp.

    Subclavian Arteries

    • Right Subclavian Artery

      • Arises from the brachiocephalic/innominate artery, behind the right sternoclavicular joint.
      • Arches upward and laterally over the pleura and between the scalenus anterior and medius muscles.
      • Becomes the axillary artery at the outer border of the first rib.

    • Left Subclavian Artery

      • Arises from the arch of the aorta in the thorax.

    Portal Circulation

    • The gastric, splenic, and mesenteric veins unite to form the portal vein.
    • Carries circulated blood through the capillaries of the stomach, spleen, pancreas, and intestines laden with nutriment – the products of digestion.
    • Breaks up into capillaries (after the manner of an artery) and distributes this blood throughout the liver.
    • Mingles with blood supplied by the hepatic artery and is collected again by small veins.
    • Unites to form the hepatic vein by which it is carried to the inferior vena cava, and by it is poured into the right auricle.
    • Branches or veins that will provide venous return or drain to the portal vein to go to the liver:
      • Short gastric veins
      • Left gastric vein
      • Coronary veins
      • Umbilical veins
      • Superior hemorrhoidal plexus
      • Retroperitoneal communications
    • High pressure in the portal vein (syndrome of portal hypertension) may cause:
      • Esophageal varices
      • Hemorrhoids
      • Caput medusae (prominent veins near the umbilicus)

    Organs/Areas Drained by Tributaries of the Inferior Vena Cava

    • Tributaries
      • Hepatic vein – Liver
      • Suprarenal vein – Adrenal glands
      • Renal vein – Kidney
      • Gonadal vein – Ovaries/testes
      • Inferior phrenic vein – Diaphragm
      • Lumbar veins – Lumbar portion of the abdomen
      • Internal Iliac vein – Muscles of the pelvic region
      • External iliac vein – Legs
      • Median sacral vein – Pelvis

    Relations of the Inferior Vena Cava

    • Posterior to the abdominal cavity
    • Lateral to the abdominal aorta
    • Medial to the right lung
    • Runs along the side of the vertebral column on its right side
    • Enters the right atrium at the lower right, back side of the heart

    Organs Drained by the Portal Vein

    • GIT, spleen, pancreas, and gallbladder.
    • Drains blood from the abdominal part of the gastrointestinal tract from the lower third of the esophagus to halfway down the anal canal.
    • Also drains from the spleen, pancreas, and gallbladder.
    • Enters the liver and breaks up into sinusoids, from which blood passes into the hepatic veins that join the inferior vena cava.

    Axillary Artery

    • 3 parts
      • 1st part
        • Begins at the outer border of the first rib.
        • Ends at the lateral border of the first rib.
        • Branches:
          • Superior thoracic artery - supplies the 1st intercostal space
          • Internal thoracic artery - supplies the mediastinum and anterior chest wall
          • Costocervical trunk:
            • Deep cervical artery - supplies deep neck muscles.
            • Superior intercostal artery - supplies the first and second intercostal spaces.
      • 2nd part
        • Begins after it passes the lateral border of the first rib
        • Ends at the lower border of teres minor.
        • Branches:
          • Thoracoacromial artery - has clavicular, pectoral, deltoid and acromial branches.
          • Lateral thoracic - runs with long thoracic nerve and supplies muscles that it traverses.
      • 3rd part
        • Begins after it exits the teres minor and ends after the lower border of teres major.

    Thoracic Aorta

    • Commences at the vertebral level T4
    • Terminates at vertebral level T12
    • Continuation of the arch of the aorta
    • Terminates as the abdominal aorta, piercing the diaphragm

    Maxillary Vein

    • Formed in the infratemporal fossa from the pterygoid venous plexus
    • Joins the superficial temporal vein to form the retromandibular vein

    Retromandibular Vein

    • Formed by the union of the superficial temporal and the maxillary veins.
    • Divides into an anterior branch that joins the facial vein, and a posterior branch that joins the posterior auricular vein to form the external jugular vein.

    External Jugular Vein

    • Formed behind the angle of the jaw by the union of the posterior auricular vein with the posterior division of the retromandibular vein.
    • Descends across the sternocleidomastoid muscle and beneath the platysma muscle.
    • Drains into the subclavian vein behind the middle of the clavicle.

    Tributaries of External Jugular Vein

    • Posterior external jugular vein from the back of the scalp
    • Transverse cervical vein from the skin and the fascia over the posterior triangle
    • Suprascapular vein from the back of the scapula

    Anterior Jugular Vein

    • Descends in the front of the neck close to the midline.
    • Joined to the opposite vein by the jugular arch just above the sternum.
    • Joins the external jugular vein deep to the sternocleidomastoid muscle.

    Internal Jugular Vein

    • Large vein receiving blood from the brain, face, and neck.
    • Starts as a continuation of the sigmoid sinus, leaving the skull through the jugular foramen.

    Internal Carotid Artery

    • Originates at the level of the upper border of the thyroid cartilage
    • Terminates in the substance of the parotid gland behind the neck of the mandible by dividing into the superficial temporal and maxillary arteries
    • Close to its origin, the artery emerges from under the sternocleidomastoid muscle, where its pulsations can be felt
    • Initially lies medial to the internal carotid artery, but as it ascends in the neck, it passes backward and lateral to it
    • Crossed by the posterior belly of the digastric and the stylohyoid

    Branches of the External Carotid Artery

    • Superior thyroid artery - upper pole thyroid gland
    • Ascending pharyngeal artery - pharyngeal wall
    • Lingual artery - tongue
    • Facial artery - tonsils, submandibular gland, face
    • Occipital artery - back of scalp
    • Posterior auricular artery - auricle, scalp
    • Superficial temporal artery - scalp
    • Maxillary artery - upper & lower jaws, muscles of mastication, the nose, the palate, and the meninges inside the skull

    Subclavian Arteries

    • Right Subclavian Artery
      • Arises from the brachiocephalic/innominate artery, behind the right sternoclavicular joint
      • Arches upward and laterally over the pleura and between the scalenus anterior and medius muscles
      • Becomes the axillary artery at the outer border of the first rib
    • Left Subclavian Artery
      • Arises from the arch of the aorta in the thorax
      • Ascends to the root of the neck and arches laterally in a manner similar to the right subclavian artery, with the scalenus anterior muscle passing anterior to the artery on each side.
      • Divides into three parts

    Subclavian Artery Branches (Specific to Head & Neck)

    • Vertebral artery
      • Runs cranially in the transverse foramina of the cervical vertebrae
      • Joins the vertebral artery on the contralateral side to form the basilar artery
      • Joins the circle of Willis

    Azygos Vein

    • Serves as an alternate pathway if the superior vena cava (or inferior) is blocked.
    • Lies on the right side of the body posterior to the inferior vena cava.
    • Found below the level of the renal veins.
    • Origin is not constant.
    • Ascends on the right side of the thoracic vertebral column.
    • Provides an alternate path for blood to the right atrium by allowing blood flow between the venae cavae when one vena cava is blocked.
    • Formed by the union of the ascending lumbar veins with the right subcostal veins at the level of the 12th thoracic vertebra.
    • Ascends in the posterior mediastinum.
    • Arches over the right main bronchus posteriorly at the root of the right lung to join the superior vena cava.
    • "Arch of the azygos vein" (arcus venae azygos) is an important anatomic landmark.
    • In rare anatomical variations, the arch can be displaced laterally, creating a pleural septum separating an azygos lobe from the upper lobe of the right lung.
    • The azygos vein is unpaired, with only one in the body (mostly on the right side).
    • Drains the back, thoracic and abdominal walls.

    Hemiazygos Vein

    • Ascends on the left side of the vertebral column posterior to the thoracic aorta, reaching as far as T9 vertebra.
    • Crosses to the right posterior to the aorta, thoracic duct, and oesophagus, joining the azygos vein.
    • Receives the inferior three intercostal veins, inferior oesophageal veins, and several small mediastinal branches.

    Accessory Hemiazygos Vein

    • Does not have the same purpose as the other two veins.
    • Begins at the medial end of the 4th or 5th intercostal space and descends on the left side of the vertebral column from T5 to T8.
    • Receives tributaries from veins in the 4th to 8th intercostal spaces and sometimes from the left bronchial veins.
    • Crosses over T7 or T8 vertebrae posterior to the thoracic aorta and thoracic duct, joining the azygos vein.
    • Sometimes joins the hemiazygos vein and opens with it in the azygos.

    Arteries that Supply the External Surface of the Anterior Thoracic Wall

    • Internal thoracic artery
      • Gives rise to two anterior intercostal arteries in each of the upper six intercostal spaces.
      • Terminates at the sixth intercostal space by dividing into the musculophrenic and superior epigastric arteries.
    • Anterior intercostal arteries
      • 12 small arteries (2 in each of the upper 6 intercostal spaces) that run laterally, 1 each at the upper and lower borders of each space.
      • Anastomoses with the deep circumflex iliac artery in the intercostal space.
      • Supply the pericardium, diaphragm, and muscles of the abdominal wall.

    Thoracoepigastric Vein

    • Alternate pathway to connect axillary and femoral veins.
    • Venous connection between the lateral thoracic vein and the superficial epigastric vein.
    • Establishes an important communication between the femoral vein and the axillary vein.
    • Especially important vein when the inferior vena cava (IVC) becomes obstructed.

    Clinical Significance of Thoracoepigastric Vein

    • Mondor’s disease
      • Tenderness at the breast area with a cord-like structure upon palpation (inflamed thoracoepigastric vein).
      • Phlebitis of the thoracoepigastric vein.

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