H E A R T

Question 1

blood flow through the heart

Answer 1

1. right atrium
2. right AV valve
3. right ventricle
4. pulmonary SL valve
5. pulmonary artery
6. lungs
7. pulmonary veins
8. left atrium
9. left AV valve
10. left ventricle
11. aortic SL valve
12. aorta

Question 2

what are the 3 layers of the heart wall?

Answer 2

1. epicardium
2. myocardium
3. endocardium

Question 3

epicardium

Answer 3

(visceral pericardium) - often infiltrated with fat

Question 4

myocardium

Answer 4

mainly cardiac muscle (contractile layer)

Question 5

endometrium

Answer 5

thin layer of endothelium

Question 6

what are the 4 heart valves?

Answer 6

prevents back flow

1. tricuspid (AV) valve
2. pulmonary (SL) valve
3. bicuspid (mitral/AV) valve
4. aortic (SL) valve

Question 7

tricuspid (AV) valve

Answer 7

connects right atrium to right vetricle

Question 8

pulmonary (SL) valve

Answer 8

connects right ventricle to pulmonary trunk

Question 9

bicuspid (mitral/AV) valve

Answer 9

connects left atrium to left ventricle

Question 10

aortic (SL) valve

Answer 10

connects left ventricle to aorta

Question 11

cardiac muscle action potential

Answer 11

upstroke: Na+ influx
plateau: Ca2+ influx
depolarization: K+ efflux

Question 12

what anatomical structure is the primary pacemaker of the heart?

Answer 12

sinoatrial (SA) node

Question 13

what are the purposes of intercalated discs in heart muscle?

Answer 13

communication to coordinate contractions

Question 14

ECG: P-wave

Answer 14

atrial depolarization (SA node)

Question 15

ECG: PQ

Answer 15

signal delay at AV node

Question 16

ECG: QRS

Answer 16

ventricles: depolarize
atrium: repolarize

Question 17

ECG: ST

Answer 17

ventricles: depolarization complete

Question 18

ECG: T-wave

Answer 18

ventricles repolarize

Question 19

what would happen in pacemaker cells became more permeable to potassium ions?

Answer 19

K+ slows depolarization, so decreased heart rate (HR)

Question 20

what would happen in pacemaker cells became more permeable to sodium ions?

Answer 20

Na+ speeds up depolarization, so increased heart rate (HR)

Question 21

tachycardia

Answer 21

fast heart rate

Question 22

bradycardia

Answer 22

slow heart rate

Question 23

what physiological events are represented by the 1st and 2nd heart sounds?

Answer 23

S1: “lubb”: closing AV valves

S2: “dupp”: closing SL valves

Question 24

relate AV and SL valves closing to ventricular systole and diastole

Answer 24

systole: AV close, SL open
diastole: AV open, SL close

Question 25

SNS affect on HR and CO

Answer 25

release NE (opens Na+ and Ca2+ to speed up depolarization) increased HR & CO

Question 26

PNS affect on HR and CO

Answer 26

release Ach (opens K+ to slow depolarization) decreased HR & CO

Question 27

what is the effect of increased or decreased systolic and diastolic blood pressure affect stroke volume?

Answer 27

increased BP Increased after load decreased stroke volume (have more resistance)

Question 28

EDV definition

Answer 28

end diastolic volume volume in ventricle at end of diastole (volume available for ejection) ~120ml

Question 29

ESV definition

Answer 29

end systolic volume volume left in ventricle at the end of systole (after ejection) ~60ml

Question 30

how would increased contractile force in the left ventricle effect ESV?

Answer 30

decrease ESV