Anatomy and Physiology of the Heart

Question 1

What is the apex of the heart?

Answer 1

-Bottom of the heart formed by tip of left ventricle and positioned just above the diaphragm to the left of the sternum at the fifth intercontinental space, midclavicular line

Question 2

What is the point of maximal impulse?

Answer 2

The physical examination landmark of the apex of the heart (5th left intercostal space, midclavicular line) which can be palpated during ventricular contraction
-Indicator of the heart’s position within the thorax

Question 3

Name the three layers of the heart.

Answer 3

Pericardium: the outermost layer
Myocardium: the middle muscular layer
Endocardium:the inner layer

Question 4

What is the function of the pericardium?

Answer 4

-Encloses and protects the heart
-Consists of two components
1. Fibrous Pericardium
2. Serous Pericardium

Question 5

What is the pericardial space?

Answer 5

The space between the parietal and visceral layer of the serous pericardoum containing 10-30ml of thin, clear fluid called pericardial fluid

Question 6

What is the myocardium?

Answer 6

The thick, middle, muscular layer that makes up the bulk of the heart wall
-Composed primarily of cardiac muscle cells which are responsible for the heart’s ability to contract

Question 7

What is the endocardium?

Answer 7

A thin layer of tissue thar lines the inner surface of the heart muscle and heart chambers
-Extensions and folds of this tissue form the valves of the heart

Question 8

What is the pulmonary circuit?

Answer 8

A small circuit including blood vessels within the lung and those carrying blood between the heart and lungs

Question 9

What is the systemic circuit?

Answer 9

A large circuit that includes coronary circulation, blood vessels within the body, and those carrying blood to and from the body

Question 10

Describe the difference in blood flow between the pulmonary artery and the pulmonary vein.

Answer 10

PULMONARY ARTERY: the right ventricle pumps venous (deoxygenated) blood through the pulmonary arteries into the lungs

PULMONARY VEIN: arterial (oxygenated) blood returns through the pulmonary vein to the left heart

Question 11

Where is the tricuspid valve?

Answer 11

Separates the right atrium from the right ventricle

Question 12

Where is the pulmonic valve?

Answer 12

Separates the right ventricle from the pulmonary arteries

Question 13

Where is the mitral valve?

Answer 13

Separates the left atrium from the left ventricle

Question 14

Where is the aortic valve?

Answer 14

Separates the left ventricle from the aorta

Question 15

What is the primary function of the valves of the heart?

Answer 15

Allows blood to flow in one direction through the heart’s chambers and prevent a backflow of blood (regurgitation)

Question 16

Which valves make up the atrioventricular valves?

Answer 16

1. Tricuspid Valve
2. Mitral (Bicuspid) Valve

Question 17

Which valves make up the semilunar valves?

Answer 17

1. Pulmonic Valve
2. Aortic Valve

Question 18

What is the function of the chordae tendinae and papillary muscles?

Answer 18

1. When the AV valves are open they and the valve leaflets form a funnel to promote blood flow into the ventricles
2. Backflow of blood into the atria is prevented by contraction of the papillary muscles and the tension in the chordae tendinae

Question 19

The closure of which valves makes up the first heart sound (S1)?

Answer 19

-Tricuspid and mitral valves
-Best heard at the apex of the heart (5th left intercostal space, midclavicular line)

Question 20

The closure of which valves makes up the second heart sound (S2)?

Answer 20

-Aortic and Pulmonic Valves
-Best heard over the second intercostal space on the left or right side of the sternum

Question 21

Describe atrial kick and it’s purpose.

Answer 21

ATRIAL KICK: atrial contraction that accounts for an additional 20-30% to ventricular filling volume
-A loss of atrial kick may result in incomplete filling of the ventricles and a reduction in cardiac output

Question 22

Name the coronary arteries.

Answer 22

1. Right Main Coronary Artery
2. Left Main Coronary Artery
   -Left Circumflex Coronary Artery
   -Left Anterior Descending
3. Posterior Descending Artery (determines dominance)