Exam Ch 14

Question 1

volume of blood pumped in one heartbeat

Answer 1

Stroke volume
EDV-ESV=SV

Question 2

% of EDV pumped

Answer 2

Ejection fraction
SV/EDV=EF

Question 3

what is usually healthy for ejection fraction

Answer 3

55-70%

Question 4

Total volume of blood pumped per minute

Answer 4

Cardiac Output (Q)

Question 5

equation for cardiac output

Answer 5

heart rate x stroke volume

Question 6

what is average total blood volume in a human body

Answer 6

5 L

Question 7

Resting cardiac output

How much does it increase during vigorous exercise

Answer 7

4.2-5.6 L/min

Increases 5-6 times

Question 8

Cardiac output in endurance athletes

Answer 8

increase stroke volume means lower heart rate

Question 9

Average HR and SV in endurance athletes

Answer 9

50 bpm
100 mL

Question 10

How does Q increase from rest to steady rate exercise

Answer 10

increases rapidly then rises gradually until it plateaus when blood flow meets the exercise metabolic requirements

Question 11

Changes in Q during exercise

Answer 11

increase rapidly then increase slower. This is because SV with plateau and then only HR is increasing

Question 12

Describes the gradual time dependent downward drift in stroke volume with concomitant HR increase during prolonged steady rate exercise

Answer 12

Cardiovascular drift

Question 13

functional syncytium

Answer 13

pumping of the heart as one unit

Question 14

increased contractility during intense exercise to enhance left ventricle filling

Answer 14

Torsional contraction

Systole: heart twists gradually, storing energy like a spring
Diastole: Abrupt untwisting allows atrial filling