Interactions between the Heart and Peripheral Vasculature

Question 1

What does the central venous pool correspond to?

Answer 1

the volume enclosed by the right atrium and great veins in the thorax

Question 2

How does TPR affect venous pressure?

Answer 2

• decrease in TPR (vasodilation) allows more blood to leave arterial side and enter venous side=increased venous pressure
• increase in TPR (vasoconstriction) holds more blood on arterial side, causing venous pressure to drop

Question 3

How does cardiac output affect central venous pressure?

Answer 3

as CO increases, less blood accumulates in central venous pool, so pressure decreases

Question 4

How does blood volume impact venous return?

Answer 4

increase in blood volume=increase in venous return; decrease in blood volume=decrease in venous return

Question 5

How does venous tone impact venous return?

Answer 5

increased venous tone (venoconstriction)=increased venous return; decreased venous tone (venodilation)=decreased venous return

Question 6

Why does the body vasoconstrict during hemorrhage when vasoconstriction limits cardiac output?

Answer 6

There’s a need to keep blood on the arterial side and maintain adequate blood pressure to perfuse critical organs.

Question 7

The mean pressure that exists in the circulatory system when cardiac output stops and the pressures within the vascular system redistribute; a measure of the fullness of the system.

Answer 7

mean circulatory pressure

Question 8

What is mean circulatory pressured determined by?

Answer 8

• volume of circulating blood

- smooth muscle venous tone of the system

Question 9

What happens when central venous pressure equals mean circulatory pressure?

Answer 9

there is no pressure gradient for venous return, so blood flow ceases

Question 10

Will an increase in peripheral venous pressure increase or decrease venous return?

Answer 10

It will increase venous return due to the pressure differential between peripheral and central veins.

Question 11

Will a decrease in central venous pressure increase or decrease venous return?

Answer 11

It will increase venous return due to negative pressure effects of the respiratory pump and cardiac suctioning.