Venous Return Flashcards Preview

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Flashcards in Venous Return Deck (16)
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1
Q

Venous return refers to the amount of blood and blood flow

A

returned back to the heart from veins

2
Q

Therefore, since CO is 5 L/min, venous return

A

also equals 5 L/min.

3
Q

Arthur Guyton correlated the relationship between 2 things to control venous return.

A

mean systemic filling pressure (MSFP) and right atrial pressure (RAP)

4
Q

MSFP is approx
RAP is approx
CO is appr

A

7 mm Hg
0 mmHg
5L/min

5
Q

As CO (or venous return) increases, CVP

A

Decreases and more blood is pumped from veins to the right atrium.

6
Q

Consequently, increases in MSFP or decreases in RAP lead to

A

increased venous return

7
Q

Venous return increases as the pressure difference

between

A

RAP and MSFP increases.

8
Q

If RAP (or CVP) is low and MSFP high, then there will be a

A

maximum change in
pressure and a maximum venous return of blood to the right
heart.

9
Q

On the other hand, if RAP increases, but there is no

change in MSFP, then there will be a small difference between the two variables and venous return will

A

decrease

10
Q

Anything that causes volume retention

A

increases MSFP.

11
Q

Alternatively, situations that decrease blood volume, such as hemorrhage and dehydration,

A

decrease MSFP and venous return.

12
Q

Peripheral veins have _____ valves that.

A

one-way direct flow of blood away from the limbs and toward the heart

13
Q

Muscle contraction causes venous_________, and muscle relaxation causes venous ______

A

compression;decompression.

14
Q

The alternative contraction and relaxation patterns cause blood to be pumped

A

back to the heart, and unidirectional valves prevent blood from flowing back toward the limbs, enhancing venous return

15
Q

Respiratory activity influences venous return to the heart by

A

augmenting the pressure difference between abdominal veins and the right atrium.

16
Q

Inspiration and intrathoracic pressure

A

decrease in intrathoracic pressure.