Module 3

Question 1

Right Atrium

Answer 1

reservoir; receives low O2 blood from Vena Cava and coronary sinus

Question 2

Ventricular Diastole

Answer 2

venous blood flows through tricuspid valve into right ventricle (80% of flow is passive)

Question 3

Atrial Kick

Answer 3

contraction of atrium; responsible for 20% of blood flow to ventricle

Question 4

Right Ventricle

Answer 4

pump contents through pulmonic valve into pulmonary artery; it is low in pressure compared to left, has thinner walls and a bellow-like contraction

Question 5

Left Atrium

Answer 5

forms most of base of heart; receives O2 rich blood from pulmonary veins (4); blood flows through mitral valve to left ventricles; walls are slightly thicker than right

Question 6

Interatrial septum

Answer 6

wall between right and left atria

Question 7

Left Ventricles

Answer 7

pumping chamber; longer and thicker than right; has smooth outflow tract; has much more and thicker trabeculae than right; blood is pushed out of ventricle once enough pressure is generated to overcome resistance of semilunar valves

Question 8

Systole

Answer 8

when the AV valves close and the semilunar valves open causing blood to be pumped into systemic circulation

Question 9

Interventricular Septum

Answer 9

between the right and left ventricle; rigid just before contraction; serves as a fixed hinge

Question 10

Inferior/Superior Vena Cava

Answer 10

a great vessel of the heart; empty low O2 blood from systemic circulation into right atrium

Question 11

Pulmonary veins (4)

Answer 11

great vessel of the heart; 2 per lung; empty O2 rich blood into left atrium

Question 12

Pulmonary artery

Answer 12

great vessel of heart; gets low O2 blood from right ventricle through pulmonic valve to lungs; branches into right and left pulmonary artery that connect for gas exchange at alveolar membrane

Question 13

Aorta

Answer 13

great vessel of heart; O2 rich blood from left ventricle enters aorta through aortic valve; blood is sent to systemic circulation via brachiocephalic trunk, left common corotid artery, and subclavian artery

Question 14

Tricuspid valve

Answer 14

AV valve; btw right atrium and right ventricle; prevents backflow of blood during ventricular systole; movement of valve is controlled by chordae tendinae (keep tension)

Question 15

Mitral Valve

Answer 15

AV valve; 2 cusped valve between left atrium and left ventricle; prevents backflow during ventricular systole; chordae tendinae are thicker, stronger and more numerous than tricuspid

Question 16

Pulmonic Valve

Answer 16

semilunar valve; 3 cusped valve btw right ventricular and pulmonary artery; prevents backflow into ventricle during right ventricular diastole; not supported by chordae tendinae or papillary muscles

Question 17

Aortic Valve

Answer 17

semilunar valve; 3 cusped valve btw left ventricle and aorta; prevents backflow during left ventricular diastole; **coronary arteries originate above cusps of this valve at 3 sinuses; also not supported by chordae tendinae; secured by fibrous ring

Question 18

Endocardium

Answer 18

inner most layer of chambers, valves, and vessels; smooth, single layer; functions to decrease RBC trauma and accumulation of platelets

Question 19

Myocardium

Answer 19

middle layer of cardiac wall; the heart muscle- mechanical contraction; striated, involuntary; capable of fast electrical spread of excitation

Question 20

Pericardium (epicardium)

Answer 20

outer most layer of cardiac wall; adheres to external wall of heart; composed of connective and adipose tissue; secures heart within thorax and allows passage of larger blood vessels and nerves that supply the heart

Question 21

Pericardial Fluid

Answer 21

fills space between parietal and visceral layers of pericardium to minimize friction

Question 22

Left coronary artery

Answer 22

passes between left atrium and pulmonary trunk and divides into LAD and LC

Question 23

Left Anterior Descending Artery (LAD)

Answer 23

supplies anterior 2/3 of interventricular septum and anterior surface of left ventricle

Question 24

Left Circumflex (LC)

Answer 24

supplies lateral and posterior walls of left ventricle

Question 25

Right coronary artery

Answer 25

supplies right atrium and right ventricles; main branch is posterior descending coronary artery

Question 26

Posterior Descending Coronary Artery

Answer 26

supplies inferior and posterior ventricles and posterior 1/3 of interventricular septum

Question 27

Coronary artery disease

Answer 27

obstruction of blood flow to myocardium can cause damage to structures that coronary arteries supply

Question 28

Coronary Sinus

Answer 28

coronary veins bring low O2 blood through myocardial capillaries to right atrium through the coronary sinus

Question 29

Cardiac Output

Answer 29

volume of blood ejected from the left ventricle to aorta in 1 minute; CO= HR X SV

Question 30

Stroke Volume

Answer 30

volume of blood ejected from ventricles per beat; determined by preload, afterload, and contractility

Question 31

Preload

Answer 31

component of SV; association between the amount of myocardial stretching at the end of diastole (filling) and volume of blood ejected during next systolic contraction (the greater the distension in diastole, the greater the volume ejected in next systole)

Question 32

Afterload

Answer 32

component of SV; resistance the ventricle must overcome during systole to propel blood into great vessels (resistance of aorta and pulmonic valve)

Question 33

Myocardial Contracility

Answer 33

component of SV; changes in force generated by myocardium; determined by specific preload/afterload conditions

Question 34

Heart Rate

Answer 34

determined by balance btw sympathetic and parasympathetic tone of NS (vagal tone)

Question 35

Cardiac Index (CI)

Answer 35

used to compare CO amongst individuals since CO is dependent on body size; calculated by dividing CO by body surface area (BSA)