Cardiac Function and Venous Return curves - Cardiovascular Phys.

Question 1

Venous return is equal to?

Answer 1

Cardiac output

Question 2

Cardiac output is equal to?

Answer 2

Venous return

Question 3

As the EDV increases, cardiac output ____

Answer 3

Increases

Question 4

As the right atrial pressure increases, the venous return is first at a plateau phase and then _____

Answer 4

Decreases

Question 5

What is the equilibrium right atrial pressure?

Answer 5

+2

Question 6

What is the equilibrium cardiac output/venous return?

Answer 6

5 L/min

Question 7

What is mean systemic filling pressure?

Answer 7

Pressure in the vasculature when there is NO flow occurring

Question 8

What value is mean systemic filling pressure?

Answer 8

+7

Question 9

How will an increase in ionotropy (contractility) affect the cardiac output curve?

Answer 9

It will shift up!

Question 10

An increase in TPR will ____ venous return

Answer 10

Decrease

Question 11

Will a change in TPR alter the mean systemic filling pressure?

Answer 11

NO

Question 12

An increase in blood volume or venoconstriction will affect the venous return curve how?

Answer 12

INCREASE venous return AND INCREASE mean systemic filling pressure

Question 13

(+) ionotropy affects to cardiac function/venous return curve

Answer 13

Increased cardiac output = increased venous return
Decreased right atrial pressure for new equilibrium
– more blood ejected

Question 14

(-) ionotropy affects to cardiac function/venous return curve

Answer 14

Decreased cardiac output = decreased venous return
Increased right atrial pressure for new equilibrium
– less blood ejected

Question 15

Blood volume changes affect which curve?

Answer 15

Venous return curve

Question 16

Ionotropy changes affect which curve?

Answer 16

Cardiac function

Question 17

Increased blood volume affects to cardiac function/venous return curve

Answer 17

Venous return curve shifts up and right

• Increased venous return = increased cardiac output
• Increased right atrial pressure and mean systemic filling pressure

Question 18

Decreased blood volume affects to cardiac function/venous return curve

Answer 18

Venous return curve shifts down and left

• Decreased venous return = decreased cardiac output
• Decreased right atrial pressure and mean systemic filling pressure

Question 19

Ionotropy

Answer 19

Contractility

Question 20

How would venoconstriction affected the venous return curve?

Answer 20

It would cause an increase in venous return!

- Curve shifts up and to the right (also increases mean systemic filling pressure)