The Cardiac Cycle

Question 1

Pressures in the cardiac chambers

Answer 1

Are constantly changing throughout the cardiac cycle

Question 2

what occurs in early diastole for both left and right ventricles?

Answer 2

Pressure drops to 0mm Hg

Question 3

pcw

Answer 3

pulmonary capillary wedge

Question 4

when is pcw used

Answer 4

intensive care setting using a swan-ganz catheter

Question 5

Right atrium average pressure

Answer 5

1-5mm Hg

Question 6

left atrium average pressure

Answer 6

2-12mm Hg

Question 7

Right ventricle average pressure systole

Answer 7

15-30mm Hg

Question 8

Right ventricle average pressure diastole

Answer 8

1-7mm Hg

Question 9

Pulmonary Artery average pressure systole

Answer 9

15-30mm Hg

Question 10

Pulmonary Artery average pressure diastole

Answer 10

4-12

Question 11

Left ventricle average pressure systole

Answer 11

90-140

Question 12

left ventricle average pressure diastole

Answer 12

5-12mm Hg

Question 13

Aorta pressure systole

Answer 13

90-140mm Hg

Question 14

Aorta pressure diastole

Answer 14

60-90mm Hg

Question 15

Cardiac Output

Answer 15

Amount of blood pumped by each ventricle in 1 minute

Question 16

what is cardiac output the product of?

Answer 16

Stroke volume and heart rate

Question 17

what is the average cardiac output?

Answer 17

4-8 liters per minute

Question 18

As cardiac output increases

Answer 18

blood pressure increases

Question 19

Stroke volume

Answer 19

The volume of blood ejected by the ventricles with each contraction

Question 20

Any effect on SV or HR

Answer 20

affects the cardiac output

Question 21

Preload

Answer 21

the degree that the muscle fiber stretches before contraction

Question 22

Preload is affected by what?

Answer 22

ventricles ability to stretch and relax

Question 23

Afterload

Answer 23

Aortic arterial pressure and vascular resistance the ventricle must overcome to eject blood or any resistance against which the ventricle must pump against to eject its volume

Question 24

Blood flow velocity depends on what?

Answer 24

Many factors

• size and shape of the vessel/chamber it is traveling through
• wall characteristics
• timing within the cardiac cycle
• flow rate
• viscosity of blood

Question 25

Flow starts with what?

Answer 25

uniformly with similar profiles, giving a flat laminar appearance

Question 26

most of the flow is traveling how fast?

Answer 26

traveling at the same velocity as the laminar flow

Question 27

where are the flow velocities the highest?

Answer 27

toward the middle of a vessel

Question 28

where can flow become turbulent

Answer 28

travels through an area of obstruction or smaller surface area