Work of the Heart

Question 1

what is stroke volume?

Answer 1

amount of blood pumped out of the heart with each systolic contraction

Question 2

what is end diastolic volume (EDV)?

Answer 2

blood in ventricles at end of filling (diastole)

Question 3

what is end systolic volume (ESV)?

Answer 3

blood remaining in ventricle after contraction (systole)

Question 4

what is the equation for stroke volume?

Answer 4

SV = EDV - ESV

Question 5

what is cardiac output?

Answer 5

amount of blood pumped out of the heart per minute

Question 6

what is the equation for cardiac output?

Answer 6

Q = SV x HR

Question 7

what is the average cardiac output?

Answer 7

5L/min

Question 8

what is ejection fraction?

Answer 8

fraction of EDV that gets ejected

Question 9

what is the equation for ejection fraction?

Answer 9

EF = SV/EDV

Question 10

what is the average ejection fraction?

Answer 10

60%

Question 11

what part of the cardiac cycle is represented from point A to B?
(little increase P, large increase V)

Answer 11

filling/diastole

Question 12

what part of the cardiac cycle is represented from point B to C?
(large increase P, no change in V)

Answer 12

isovolumic contraction

Question 13

what part of the cardiac cycle is represented from point C to D?
(increase P, decrease V)

Answer 13

ejection/systole

Question 14

what part of the cardiac cycle is represented from point D to A?
(no change V, large decrease P)

Answer 14

isovolumetric relaxation

Question 15

what occurs at point A?

Answer 15

AV valve opens

Question 16

what occurs at point B?

Answer 16

AV valve closes (S1)

Question 17

what occurs at point C?

Answer 17

aortic valve opens

Question 18

what occurs at point D?

Answer 18

aortic valve closes (S2)

Question 19

what point represents ESV?

Answer 19

A

Question 20

what point represents EDV?

Answer 20

B

Question 21

what point represents S1?

Answer 21

B (AV valve)

Question 22

what point represents S2?

Answer 22

D (aortic valve)

Question 23

what represents S3?

Answer 23

A to B (rapid filling)

Question 24

What is the cardiac output?
- resting HR = 70bpm
- arterial P = 130/85mmHg
- left ventricular V = 50mL (A/D) -> 150mL (B/C)

Answer 24

Q=HRxSV
= 70 x (150-50)
= 7000mL/min

Question 25

what is the ventricular ejection fraction?
- resting HR = 70bpm
- arterial P = 130/85mmHg
- left ventricular V = 50mL (A/D) -> 150mL (B/C)

Answer 25

EF = (EDV-ESV)/EDV
= ((150-50)/150) x100%
= 66.7%