Anatomy of the Heart - Cardiovascular System

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Questions and Answers

What is the main function of the pericardial cavity?

To protect and anchor the heart

To allow for the heart to work in a relatively friction-free environment (correct)

To store blood during high-pressure conditions

To regulate the heartbeat

Which of the following vessels conveys blood away from the heart?

Pulmonary trunk (correct)

Right pulmonary veins

Superior venae cavae

Left pulmonary artery

What is the outermost layer of the heart wall?

Myocardium

Endocardium

Fibrous skeleton

Epicardium (correct)

What is the function of the fibrous pericardium?

To prevent overfilling of the heart with blood Signup and view all the answers

Which of the following vessels returns blood to the heart?

Superior venae cavae Signup and view all the answers

What is the innermost layer of the heart wall?

Endocardium Signup and view all the answers

Which of the following vessels is not responsible for supplying the heart with oxygenated blood?

Superior vena cava Signup and view all the answers

What is the primary function of the atrioventricular (AV) valves in the heart?

To prevent backflow of blood into the ventricles Signup and view all the answers

Which of the following statements is true about the path of blood through the heart and lungs?

Blood flows from the right atrium to the right ventricle to the pulmonary arteries Signup and view all the answers

What is the main function of the coronary circulation?

To provide a functional blood supply to the heart muscle itself Signup and view all the answers

Which of the following valves lies between the left ventricle and the aorta?

Aortic semilunar valve Signup and view all the answers

What is the approximate volume of blood in an individual weighing 154 pounds?

5 quarts/liters Signup and view all the answers

What is the primary function of the lymph nodes in the lymphatic system?

To filter and clean the lymph before returning it to the blood Signup and view all the answers

What percentage of the total blood volume is composed of blood plasma?

55% Signup and view all the answers

Which of the following is not a function of blood?

Regulating body temperature Signup and view all the answers

What is the correct pathway of blood from the lungs to the heart?

Lungs → pulmonary veins → left atrium Signup and view all the answers

What is the term for the fluid that occupies the space between all cells of the body?

Interstitial fluid Signup and view all the answers

What is the primary function of the spleen in the lymphatic system?

To remove old red blood cells from the blood supply Signup and view all the answers

What is the percentage of water in lymph?

95% Signup and view all the answers

What is the function of the tonsils in the lymphatic system?

To filter bacteria and produce white blood cells Signup and view all the answers

How does the lymph move through the lymphatic system?

Through both skeletal muscle action and respiratory movement Signup and view all the answers

What is the primary function of the white pulp of the spleen?

To remove, store and produce white blood cells Signup and view all the answers

Study Notes

Heart Anatomy

The heart is approximately the size of a fist
Located on the superior surface of the diaphragm, left of the midline, and anterior to the vertebral column, posterior to the sternum
Coverings of the heart:
- Pericardium: a double-walled sac around the heart
- Fibrous pericardium: a superficial layer
- Serous pericardium: a deep two-layer layer (parietal and visceral layers)
- Pericardial cavity: a fluid-filled space between the parietal and visceral layers

Function of the Pericardium

Protects and anchors the heart
Prevents overfilling of the heart with blood
Allows for the heart to work in a relatively friction-free environment

Heart Wall

Epicardium: visceral layer of the serous pericardium
Myocardium: cardiac muscle layer forming the bulk of the heart
Fibrous skeleton of the heart: a layer of connective tissue
Endocardium: endothelial layer of the inner surface of the heart

External Heart: Major Vessels

Vessels returning blood to the heart:
- Superior and inferior venae cavae
- Right and left pulmonary veins
Vessels conveying blood away from the heart:
- Pulmonary trunk (splits into right and left pulmonary arteries)
- Ascending aorta

External Heart: Vessels that Supply/Drain the Heart

Arteries: mainly coronary arteries
Veins: small cardiac, anterior cardiac, and great cardiac veins

Atria and Ventricles

Atria: receiving chambers of the heart
Blood enters right atria from superior and inferior venae cavae and coronary sinus
Blood enters left atria from pulmonary veins
Ventricles: discharging chambers of the heart
Right ventricle pumps blood into pulmonary arteries
Left ventricle pumps blood into the aorta

Pathway of Blood Through the Heart and Lungs

Right atrium → tricuspid valve → right ventricle
Right ventricle → pulmonary semilunar valve → pulmonary arteries → lungs
Lungs → pulmonary veins → left atrium
Left atrium → bicuspid valve → left ventricle
Left ventricle → aortic semilunar valve → aorta
Aorta → systemic circulation

Coronary Circulation

Functional blood supply to the heart muscle itself

Heart Valves

Ensure unidirectional blood flow through the heart
Atrioventricular (AV) valves: prevent backflow into the atria when ventricles contract
Semilunar valves: prevent backflow of blood into the ventricles
Aortic semilunar valve: lies between the left ventricle and the aorta
Pulmonary semilunar valve: lies between the right ventricle and pulmonary trunk

Blood and Lymph System

Blood: a fluid consisting of formed elements and plasma
Produced by bone marrow
Volume depends on body weight (approximately 5 quarts/liters for a 154-pound individual)
Functions: transportation of respiratory gases, chemicals, and cells that protect the body from foreign substances

Vascular Tree

Hierarchical network of arteries, arterioles, capillary beds, veins, and venules
Characterized by an inner layer of endothelium and an outer layer of basement membrane

Blood Plasma

Fluid part of the blood (55% of total blood volume)
Clear or straw-colored
Composed mostly of water and proteins

Lymph

Clear, nearly colorless, alkaline fluid
Occupies the space between all cells of the body (interstitial fluid)
95% water
Seeps in and out through the walls of capillaries
Mostly fluid from blood plasma

Lymphatic System

Connected to the circulatory system
Consists of capillaries, vessels, ducts, and nodes
Transports lymph one-way back to the bloodstream
No pump, but lymph moves via skeletal muscle action, respiratory movement, and contraction of smooth muscle in vessel walls

Lymph Nodes

Filters, slowing down and cleaning the lymph before returning it to the blood

Accessory Organs to the Lymphatic System

Spleen:
- Removes old red blood cells from the blood supply
- Removes, stores, and produces white blood cells
Tonsils:
- Filter bacteria and produce white blood cells

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Description

Learn about the anatomy of the heart, its location, and coverings. Understand the structure of the pericardium and its layers.