Cardiovascular Physiology

Question 1

Which phase of the cardiac muscle contraction has Na gates open and Na influxes into cardiac myocytes causing rapid depolarization?

Answer 1

Phase 0

Question 2

Which phase of the cardiac muscle contraction has closure of Na gates; K gates open with K efflux causing initial repolarization?

Answer 2

Phase 1

Question 3

Which phase of the cardiac muscle contraction Ca influx through L-type Ca channels the plateau phase; K efflux is stopped?

Answer 3

Phase 2

Question 4

Which phase of the cardiac muscle contraction has inactivation of Ca influx with continuation of K efflux rest of repolarization?

Answer 4

Phase 3

Question 5

Which phase of the cardiac muscle contraction removal of excess Na and Ca with restoration of the membrane potential?

Answer 5

Phase 4

Question 6

What law is directly proportional to the venous return

Answer 6

Frank-Starling’s law

Question 7

What is the 1st heart sound due to?

Answer 7

closure of tricuspid and mitral valve (LUB)

Question 8

What is the 2nd heart sound due to?

Answer 8

closure of the pulmonary and aortic valve (DUB)

Question 9

What sound is seen in congestive heart failure and is heard after the 2nd heart sound?

Answer 9

3rd sound

Question 10

What sound is hear before the 1st heart sound and is seen in hypertrophic cardiomyopathy and atrial contraction?

Answer 10

4th sound

Question 11

Which phase of the cardiac cycle involves an increase in pressure without change in volume that occurs between the closure of the mitral valve and opening of the aortic valve?

Answer 11

Isovolumic contraction

Question 12

How much blood is ejected from the ventricle during the cardiac cycle?

Answer 12

70/120ml

Question 13

Which phase of the cardiac cycle involves a decrease in ventricular pressure without a change in volume that occurs between the closing of the aortic valve and opening of the mitral valve?

Answer 13

Isovolumic relaxation

Question 14

What is the intrinsic rhythmicity of the SA node?

Answer 14

80-100 times/min

Question 15

What is the intrinsic rhythmicity of the AV node?

Answer 15

40-60 times/min

Question 16

Where is the rate of depolarization the fastest?

Answer 16

SA node

Question 17

Where is the rate of depolarization the slowest?

Answer 17

Purkinje fibers

Question 18

Where is the conduction velocity the fastest?

Answer 18

Purkinje fibers

Question 19

Where is the conduction velocity the slowest?

Answer 19

AV node

Question 20

What causes a prolonged PR interval?

Answer 20

1st degree AV block

Question 21

What causes progressive prolongation of the PR interval with dropped beats?

Answer 21

2nd degree AV block

Question 22

What causes P waves that are not followed by QRS complexes?

Answer 22

3rd degree AV block

Question 23

What is the product of Cardiac output multiplied by Peripheral resistance?

Answer 23

Blood Pressure

Question 24

What is the product of Stroke volume multiplied by heart rate?

Answer 24

Cardiac Output

Question 25

What is the equation of Stroke volume?

Answer 25

EDV-ESV

Question 26

What are the 2 main mechanisms for Blood pressure control?

Answer 26

baroreceptors (fast) and renin-angiotensin-aldosterone (slow)

Question 27

T/F: A drop in blood pressure causes an increase in HR?

Answer 27

True

Question 28

T/F: pressure in the vessel wall is inversely proportional to to the diameter of the blood vessel

Answer 28

True

Question 29

What law describes the flow rate of fluid through tube?

Answer 29

Poiseuille’s law