ANAT_LC6a_The-Cardiovascular-System.pdf

UNIVERSITY OF NORTHERN PHILIPPINES ANATOMY LC6 CARDIOVASCULAR SYSTEM COLLEGE OF MEDICINE, BA...

UNIVERSITY OF NORTHERN PHILIPPINES ANATOMY LC6 CARDIOVASCULAR SYSTEM COLLEGE OF MEDICINE, BATCH 2026 ANATOMY Transcribers: Achacoso, Acosta, Ammiyao, Anulacion, Avecilla, Busaing Dr. L. Asuncion-Viado | Nov 2022 Editors: Abrero, Almeron, Anaper COURSE OUTLINE ○ There are landmarks here that are used in assessing the heart, like the I. THORAX manubriosternal joint or the Angle of Louis, the suprasternal notch, II. STERNUM which is usually important in assessing patients with stridor, and this A. Parts of the Sternum 1st part of the costal cartilage wherein the ribs are attached. When III. RIBS you move your hand laterally, you can feel your clavicle, and below IV. PERICADIUM that, you can’t feel your 1st rib because it is deprived. The space below A. Parts of the Pericardium the clavicle is the 1st ICS (intercostal space), the 2nd bone is the 2nd V. BECK’S TRIAD rib, and then you count 1, 2, 3 until the 5th ICS, wherein you will see VI. PERICARDIAL SINUSES the apex. A. Oblique Sinus B. Transverse Sinus A. Parts of the Sternum VII. NERVE SUPPLY OF PERICARDIUM a. MANUBRIUM A. Phrenic Nerve Upper part of the sternum B. Vagus Nerve and Sympathetic Branches Articulates with the body of the sternum at the VIII. HEART manubriosternal joint A. Surfaces of the Heart Articulates with the clavicles and with the 1st costal cartilage B. Borders of the Heart and the upper part of the 2nd costal cartilages on each side C. Structures of the Heart Lies opposite the 3 and 4 thoracic vertebrae D. Chambers of the Heart o Attached to the clavicle superiorly and joint that IX. Fibrous Cardiac Skeleton attaches the manubrium to the body - the Angle of Louis which is important in assessing Jugular venous I. THORAX pressure then the clavicle attached upward, Region of the body between the neck and abdomen superiorly the other will be the 1st intercostal ribs Flattened anteriorly and posteriorly but rounded laterally cartilage of the 1st rib. o Posteriorly lies opposite the 3 and 4 thoracic Thoracic cage - framework walls vertebrae ○ vertebral column posteriorly ○ ribs and intercostal spaces laterally b. BODY OF THE STERNUM ○ sternum and costal cartilages in anteriorly Articulates above with the manubrium at the ○ suprapleural membrane superiorly manubriosternal joint or Angle of Louis and below with the ○ diaphragm inferiorly xiphoid process at the xiphisternal joint on each side Articulates with the 2nd to 7th costal cartilage (where the Protects the lungs and heart body of the sternum attaches) ○ any concussion on the rib cage will affect the lungs and the heart Middle of Manubrium and the body of the sternum is where Provides attachment for the muscles of the thorax, upper extremity, the 2nd costal cartilage abdomen, and back Between the last part of the body of the sternum and xiphoid is where the 7th costal cartilage 7th ribs have two attachments: II. STERNUM o Inferior part of the body Lies in the midline of the anterior chest wall (top most is the external notch; Upper part of the xiphoid process these frontal parts of the thorax are important in assessing the heart in physical examination) Sternal Angle (Angle of Louis) It is a flat bone divided into 3 parts: Feel the suprasternal notch, then go down. You will feel a a. Manubrium lump (Sternal angle of Louis) b. Body of the sternum Join the manubrium and the body of the sternum c. Xiphoid process Presence of transverse glitch which lies at the level of the 2nd costal cartilage Posteriorly, the presence of the sternal angle of Louis can be seen between T4-T5 Landmark from behind would be T9 The Sternal angle of Louis is an important landmark for the assessment of the Jugular Venous pressure Jugular venous pressure (neck part) measures the pressure of the right atrium Jugular vein collapses when you inhale Jugular arteries will not collapse, pulsatile Assessment of JVP (Jugular Venous Pressure) The patient lies down with the neck in a 60-degrees angle position, puts the ruler in the sternal angle of Louis, and gets another piece of paper or another ruler that will measure the highest point of oscillation of the jugular venous pressure. It will be prominent. Put the piece of paper or another ruler perpendicular to the ruler. Add 5 cm. (e.g: you got 3 cm in the ruler, add 5cm that will make it 8 cm) ○ 5 cm is the measurement between the sternal angle of Louis to the right atrium. Figure 1. Sternum Page 1 of 9 [ANATOMY] 1.06 CARDIOVASCULAR SYSTEM – Dr. Leslie Asuncion-Viado Normal JVP: 5-8 cm o In between the two is a space (Pericardial fluid) > 8 – Congestion o The fibrous pericardium and the parietal part of the < 5 – Hypovolemia serous pericardium will be going upward to the great vessel c. XIPHOID PROCESS o The visceral part will be connected to the parietal Thin plate of cartilage that becomes ossified at its proximal part of the pericardium. They will meet in the base of end during adult life the heart. No ribs or costal cartilages are attached to it III. RIBS 12 ribs True ribs have an attachment to the sternum (1-7 ribs) False ribs are attached only in the 7th rib through a cartilage (8, 9 and 10 ribs) Floating ribs have no anterior attachment (11 and 12 ribs) IV. PERICARDIUM Within the center of the thorax Outer part of heart It is a fibroserous sac (composed of fibrous part and serous part which encloses the heart up to the roots of the great vessel) Function: Restrict the movement of the heart as a whole ○ Contain the heart in one area ○ Contains fluids that will lubricate the heart as it contracts, so that there will be no friction that will happen in each contraction Location: middle of the mediastinum, which is posterior to the body of the sternum and second to the six cartilages. Figure 3. Parts of the Pericardium ○ Posteriorly, will be seen on T5 -T8 c. Pericardial Cavity Approximately 50 ml Acts as a lubricant to facilitate the movement of the heart Problem when the pericardial fluid increase: o Cardiac Tamponade - is the accumulation of fluids between the visceral and the parietal part of the serous pericardium of more than 100ml. It can be caused by inflammation, infection (TB, viral, or bacterial and even gout) If not addressed immediately, the fluid inside will restrict the heart to expand during diastole Figure 2. Pericardium (Normal) A. Parts of the Pericardium a. Fibrous Pericardium Strong fibrous part of the sac Firmly attached below to the central tendon (goes up then fuses to the great vessel) Attached in front to the sternum by the sternopericardial ligaments Outermost part Figure 4. Pericardial cavity b. Serous Pericardium Lines the fibrous pericardium Innermost part V. BECK’S TRIAD Two Parts of the Serous Pericardium an indication that there is impending cardiac tamponade 1. Parietal Layer signs to watch out for patient suspected with cardiac tamponade: the outer part of the serous membrane ○ Hypotension - occurs because the heart is hindered in its ability to Lines the fibrous pericardium pump blood. When the heart cannot work efficiently, the rest of the Reflected around the roots of the great body does not get supplied with the necessary amount of blood. This vessels to become continuous with the can result in the body going into shock and even cardiac arrest. visceral layer ○ Jugular vein distention - due to the pressure exerted on the right Holds the heart in place in the chest ventricle, diastolic filling decreases. This causes blood to back up into cavity and protects from infections the right atria and the veins that return blood to the heart, most 2. Visceral Layer notably the jugular veins. In a patient with cardiac tamponade, jugular Innermost part vein distention will be present even when they are sitting upright. Closely attached to the heart ○ Muffled heart sound - occurs because of the insulating effect of the Often called epicardium fluid in the pericardial sac. When sound travels through fluid, it sounds distant or suppressed because it is traveling through a thicker median. Page 2 of 9 [ANATOMY] 1.06 CARDIOVASCULAR SYSTEM – Dr. Leslie Asuncion-Viado Figure 5. Cardiac Tamponade VI. PERICARDIAL SINUSES are formed as a consequence when the heart bends during the embryonic development Figure 8. Transverse sinus during Cardiac surgery spaces in between the heart VII. NERVE SUPPLY OF PERICARDIUM Figure 6. Pericardial Sinuses A. OBLIQUE SINUS  Found in the posterior portion of the heart  It is a reflection of the serous pericardium around the great vessels  Bounded laterally by the entrance of the pulmonary veins and inferiorly by the orifice of the inferior vena cava  Forms an inverted U-shaped cul-de-sac  Runs along the long axis of the heart from the apex to the ascending aorta Figure 9. Nerve supply of Pericardium B. TRANSVERSE SINUS A. Phrenic Nerve  Short horizontal space (superiorly) Supplies:  Lies between the reflection of the serous pericardium around the o Outer portion of the pericardium (Fibrous pericardium) aorta and pulmonary trunk and the reflection around the large veins o Parietal layer of serous pericardium  The transverse pericardial sinus can be used to identify and A mixed motor/sensory nerve which originates from the C3-C5 spinal subsequently ligate the arteries of the heart during coronary bypass nerves in the neck grafting. Important for breathing because it provides exclusive motor control  During cardiac surgery, after the pericardial sac is opened anteriorly, of the diaphragm, the primary muscle of respiration a finger is passed through the transverse sinus of the pericardium, posterior to the aorta and pulmonary trunk.  A temporary ligature is passed through the transverse sinus around the aorta and pulmonary trunk. The tubes of the heart-lung machine are inserted into these vessels and a ligature is tightened. Figure 10. Phrenic nerve B. Vagus Nerve and Sympathetic Branches Supplies: Figure 7. Heart Sinuses o Visceral layer of the serous pericardium the tenth cranial nerve or CN X, and interfaces with the parasympathetic control of the heart, lungs, and digestive tract Page 3 of 9 [ANATOMY] 1.06 CARDIOVASCULAR SYSTEM – Dr. Leslie Asuncion-Viado VIII. HEART Hollow muscular organ Pyramid shaped Lies within the pericardium in middle of the mediastinum Connected at its base to the great blood vessels Lies freely within the pericardium Coronary arteries - are embedded beneath the fats in the AV and IV grooves Four chambers: two atria and two ventricles Making a fist is the size of a normal heart Heart is not really in the middle. 1/3 is on the right side. 2/3 is on the left side. Tilted to the left. Atrioventricular groove separates the atria from the ventricles AV grooves contains the coronary arteries: Right AV groove will contain the right coronary artery Left AV groove will contain left anterior descending Interventricular groove separates the right and left ventricle Figure 12. Schematic illustration of the heart showing orientation, surfaces, and margins B. BORDERS OF THE HEART Right Border: o Formed by the right atrium Left Border: o Formed by the left atrium/auricle BELOW & inferior portion of left ventricle Inferior/ Lower Part: o Mostly bounded by right ventricle o It is usually not palpated not unless the right ventricle is big Apex o Formed by left ventricle, the tip of the heart NOTE: Border is important to recognize when examining the anteroposterior and lateral view of radiographs of the heart. Figure 11. Grooves of the Heart A. SURFACES OF THE HEART Sternocostal surface (anterior surface) o Formed mainly by the right atrium and the right ventricle which are separated by vertical atrioventricular groove/sulcus o Right border - right atrium o Left border - left ventricle and part of the left auricle o Right ventricle is separated from the left ventricle by the anterior interventricular groove Diaphragmatic surface (inferior surface) o Formed mainly by the right and left ventricles, which are separated by the posterior interventricular groove o Heart lies on this surface o Formed also by the inferior surface of the right atrium where Figure 13. Borders of the Heart inferior vena cava opens Base of the Heart (posterior surface) To view the left atrium and the right ventricle, ask for the lateral o Formed mainly by the left atrium with the openings of the view of the heart in x-rays because if the right ventricle is enlarged, pulmonary veins and, to a lesser extent, by the right atrium it will obscure the anterior surface of the heart between the o Lies opposite the apex sternum. Lateral view of radiographs of the heart is important o Called base due to its pyramid shape especially in children with congenital anomalies. Apex o Tip of the heart o Formed by the left ventricle o Directed downwards, forward, to the left o Lies at 5th intercostal space, in younger individuals or in children, it is in the 4th ICS, left mid-clavicular line o 3.5 inches (9 cm) from the midline (laterally) o Apex beat can usually be seen and palpated in the living patient o It is important in assessing whether the patient’s heart is enlarged or not. The location of apex is important because once it is misplaced it means that the heart is enlarged, especially the in the left ventricle. Figure 14. Normal Radiograph/Chest X-ray of the Heart Page 4 of 9 [ANATOMY] 1.06 CARDIOVASCULAR SYSTEM – Dr. Leslie Asuncion-Viado C. STRUCTURES OF THE HEART o Inner portion: Smooth-walled Walls of the Heart o Anterior part of Main Cavity o Layers: epicardium, myocardium, endocardium (3 layers) Musculo tendineae – roughened surface o Myocardium usually trabeculated Muscle part (Cardiac muscle) Embryologically came from primitive atrium o Epicardium o In the right atrial cavity, the fossa ovalis is usually Outer part seen but it is closed Covered externally with serous pericardium the outermost covering of the heart or part of the heart which is also known as the visceral part of the serous pericardium o Endocardium Innermost layer Lined internally with a layer of endothelium □ The endothelium serves as a barrier or protection from toxins. If damaged, the heart will be exposed to chemicals/ toxins that can damage the heart. Figure 14. Opened right atrium: Right Lateral view Auricle – small outpouching o Roughened or trabeculated by bundles of a muscle Figure 12. The Walls of the Heart. The heart has three distinct layers namely epicardium, fiber called musculi pectinate, the ridges or myocardium, and endocardium roughened surfaces of right auricle o Embryologically from primitive atrium 2 Septums (interatrial and interventricular septum) Sulcus Terminalis o Fibrous skeleton o Vertical Groove outside the heart Forms the basis of electrical discontinuity between o Junction between the right atrium and right auricle atria and ventricles o Remember: Atrioventricular Groove is where Sulcus o Fibrous ring Terminalis is located (Outside) Supports bases of cusps Crista Terminalis Prevent stretching o Ridge inside the heart Incompetence o Boundary between atrium proper and the right auricle o Remember: Inner Cavity of the Right Atrium, posterior to Sulcus Terminalis (Inside) 4 Openings: 1. Superior Vena Cava Opens into the upper part No Valve Returns the blood to the heart from the upper half of the body 2. Inferior Vena Cava Opens into the lower part Guarded by a rudimentary, nonfunctioning valve Eustachian Valve – can cause obstruction to blood flow and thrombosis becoming prominent Returns the blood to the heart from the lower part of the body 3. Coronary Sinus Figure 13. Fibrous skeleton Drains most of the blood from the heart wall Between the inferior vena cava and the D. CHAMBERS OF THE HEART (4) atrioventricular orifice Right side: It is guarded by a rudimentary, o Right Ventricle nonfunctioning valve o Right Atrium Thebesian Valve Left side: The coronary sinus is located on the posterior o Left Ventricle (inferior) side of the heart and receives almost o Left Atrium all of the deoxygenated blood from the vasculature of the heart. The coronary sinus a. RIGHT ATRIUM (RA) opens into the right atrium anteriorly and Main Cavity inferiorly to the orifice of the inferior vena o Posterior to Crista terminalis cava. o Derived embryologically from sinus venosus Page 5 of 9 [ANATOMY] 1.06 CARDIOVASCULAR SYSTEM – Dr. Leslie Asuncion-Viado 4. Right Atrioventricular Orifice o Funnel-shaped narrowing Anterior to the Inferior vena cava o Approaches the pulmonary orifice Guarded by TRICUSPID VALVE o Constitutes the Right Ventricular Outflow Tract Tricuspid valve guards the right atrium from (RVOT) the right ventricle o Thicker muscles than RA Fetal Remnants: o Cross Section: Crescent-shaped Anulus Ovalis Trabeculae Carnae o Structure that lies in the atrial septum o Sponge-like structure o Ring like Margin o Internal projecting ridges formed of muscle bundles o Superior Fossa Ovalis o 3 Types: o Formed from the lower edge of the Septum Secundum 1. Papillary Muscles Fossa Ovalis  Project inward o Shallow depression  Connects Chordae tendineae to the o Site of the Foramen Ovale in fetus ventricular wall to prevent prolapse of o Floor represents the persistent septum primum of the the leaflet heart  Bases attached to the ventricular wall  Upper Portion attached to chordae tendineae to the cusps of the Tricuspid Valve 2. Moderator Band  Crosses ventricular cavity from septum to ventricular wall  Passageway of the right bundle branch of the atrioventricular bundle  Resists over distension of the ventricular wall 3. Ridges Figure 15. Normal Fetal Heart  Found in ventricular walls Figure 18. Interior view of the Right Ventricle Figure 16. Interior of the Right Atrium and the Right Ventricle. Note the location of the Fetal Remnants Figure 17. Internal View of Right Atrium Figure 19. Bicuspid valve is where blood passes through from the left atrium b. RIGHT VENTRICLE (RV) to the left ventricle. The chordae tendinae are fibrous cords that anchor AV Connects the RA and Pulmonary Trunk valves to papillary muscles and prevent valves from opening in the wrong RA→ RV → Pulmonary Trunk direction Infundibulum Page 7 of 9 [ANATOMY] 1.06 CARDIOVASCULAR SYSTEM – Dr. Leslie Asuncion-Viado TRICUSPID VALVE Located posterior to RA (RA is more anteriorly located than o Guards AV orifices, it has three leaflets/cusps: the LA) Anterior cusp Forms mostly the base of the heart Septal cusp (attached to septum) Lies behind the oblique sinus and the serous pericardium Inferior cusp Inside is smooth o With cusps from folds of endocardium Auricle has ridges o Bases attached to fibrous skeleton 4 pulmonary veins (no valves) open into LA o Free edges and ventricular surfaces attached to Main cavity or the inside has smooth part (PECTINATE chordae tendineae MUSCLE) and auricle has ridges Chordae tendineae prevents prolapse No crista terminalis When there is myocardial infarction, there is 5 openings (4 pulmonary valves and left atrioventricular poor supply of blood into the heart’s muscles. opening (5th)) Therefore, the chordae may be detached or Blood flow goes into the left ventricle and is guarded by the not fully functioning well so there will be mitral valve prolapse of the tricuspid leaflet causing tricuspid regurgitation. It is very important that the chordae tendineae and the papillary muscles are very good or functioning well to prevent prolapse of the tricuspid valves. PULMONIC VALVE LEAFLETS o Guards pulmonary orifice o With cusps from folds of endocardium o Curves and Margin are attached to arterial wall o Cusps opens towards the pulmonary trunk o No chordae nor papillary muscles attached o Has sinus o 1 posterior (left) and 2 anterior cusps (L & R) o Anterior, septal and inferior cusps (just like tricuspid valve) o If valve is open - cusp is collapsed o During diastole, cusp is filled up and valve will close Figure 22. View of the Left Atrium Figure 20. Atrioventricular valves are tricuspid valve (right side) and bicuspid/mitral valve (left side). Aortic and pulmonary valves are semilunar valves Figure 23. Left Atrium and Left Ventricle d. LEFT VENTRICLE (LV) Communicate with LA and Aorta (Blood from LA goes to LV then to the aorta) Aortic vestibule (LVOT or left ventricular outflow tract) - below the aortic orifice o synonymous to infundibulum in Right ventricle Cross section – circular 3x thicker than RV 6x higher BP than RV because it will have to overcome the pressure in the systemic circulation during systole Well-developed trabeculae carneae like RV o With 2 papillary muscles (because it has only 2 mitral valves) o no moderator band MITRAL VALVE Figure 21. Posterior view of Pulmonary Valve o Guards atrioventricular orifice (between the left atrium and left ventricle) c. LEFT ATRIUM (LA) o 2 cusps (anterior and posterior) Has main cavity and auricle Page 7 of 9 [ANATOMY] 1.06 CARDIOVASCULAR SYSTEM – Dr. Leslie Asuncion-Viado o Anterior mitral valve is larger than posterior mitral valve o attached to fibrous skeleton and chordae tendineae o their bases are attached to fibrous skeleton and the free edges are attached to chordae tendineae Figure 27. Aortic valve has 3 cusps: right, left and posterior (non-coronary) IX. FIBROUS CARDIAC SKELETON Pulmonic and aortic valve - no fibrous skeleton; attached immediately to their corresponding walls The fibrous cardiac skeleton is a dense connective tissue that forms the heart wall aside from the cardiac muscle tissue consisted of four interconnected fibrous rings (4 dense connective tissue rings) ○ Pulmonary fibrous ring Figure 4. Coronal cut of the left side of the heart ○ Aortic fibrous ring ○ Right atrioventricular fibrous ring ○ Left atrioventricular fibrous ring surround the atrioventricular, pulmonary, and aortic orifice valve orifices (most especially the mitral and tricuspid where in the bases of leaflets are attached to rings) continuous with atrial and ventricular septum Functions: ○ Separate the muscular walls of the atria from those of ventricles but provide attachment for the muscle fibers ○ Support & attachment for the bases of valve cusps  Tricuspid and mitral valves are attached to fibrous skeleton because fibrous ring supports the base of the cusps/valves to prevent stretching of valves when the heart is enlarged □ If valves are stretched, they will not close properly causing regurgitation or leaking of blood towards the previous chamber Figure 25. The leaflets are attached to and supported by a ring of tough, fibrous tissue  Prevent the valves from stretching and becoming called annulus. The annulus helps to maintain the proper shape of the valve. The incompetent valves are supported by chordae tendineae attached to the papillary muscles.  Keep valve orifices patent ○ Passageway of electrical impulses AORTIC VALVE  Electrical insulation between atria and ventricles o Guards aortic orifice (from left ventricle to aorta)  Electrical discontinuity from atria & ventricles o It has 3 leaflets: 1 anterior (right) and 2 posterior (left  Fibrous skeleton serves as a traffic light wherein the electrical and posterior) impulse coming from the RA going to the ventricle will have a o Contains sinuses slight delay of the cardiac activity of ventricular muscles to o Coronary arteries allow filling time of ventricles The right, left and posterior cusps, are renamed into right aortic coronary, left coronary cusp and non-coronary cusp, respectively, because these cusps do not contain coronary artery Figure 28. The fibrous skeleton of the heart anchors the valves of the heart, and gives attachment to the myocardium above and below. It consists of 4 fibrous rings, each surrounding one of the valves (aortic, pulmonary, mitral and tricuspid), plus the membranous part of the interventricular septum. Figure 26. Heart coronal section exposes the four chambers: two atria and two ventricles. Septum divides the left and right side of the heart. Page 8 of 9 [ANATOMY] 1.06 CARDIOVASCULAR SYSTEM – Dr. Leslie Asuncion-Viado Figure 29. Fibrous cardiac skeleton - anchors the valves of the heart TEST YOURSELF 1. What are the three manifestations of cardiac tamponade? a. Distant lung sounds, Hypotension, Jugular vein distention b. Distant heart sounds, Hypertension, Jugular vein distention c. Muffled heart sounds, Hypotension, Jugular vein distention d. Muffled lung sounds, Hypertension, Distant heart sound 2. It acts as a lubricant to facilitate the movement of the heart. a. Pericardial fluid b. Pericardial cavity c. Pericardial sinuses d. Pericardium 3. It forms an inverted U-shaped cul-de-sac. 4. Opening of the heart which has No Valve a. Inferior Vena Cava b. Superior Vena Cava c. Coronary Sinus d. Right Atrioventricular Orifice 5. Innermost layer of the Walls of the heart. Lined with a layer of endothelium a. Myocardium b. Epicardium c. Endocardium d. Epimysium 6. Structure that lies in the atrial septum. It has a ring like structure and it is formed from the lower edge of the Septum Secundum a. Fossa Ovalis b. Crista terminalis c. Anulus Ovalis d. Trabeculae Carneae 7. Which of the following structure/s is/are located in the anterior part of the heart? a. Sternum b. Costal Cartilages c. A and B d. None of the above 8. This is an important groove of the heart that separates the right and left ventricles. a. Intraventricular groove b. Atrioventricular groove c. Semilunar groove d. Interventricular groove 9. How many openings are there in the right atrium? a. 4 b. 2 c. 3 d. 5 10. What structure of the Left Ventricle is synonymous with the Infundibulum of the Right Ventricle? a. Trabeculae Carnae b. Fossa Ovalis c. Aortic Vestibule d. Papillary Muscles Page 9 of 9