Cardiac output regulation

Question 1

What controls the cardiac output

Answer 1

Venous return

Question 2

EX. venous return increases, what will happen to cardiac output

Answer 2

As venous return increases, cardiac output to the systemic circulation will increase

Question 3

EX. venous return increases, what will happen to cardiac output

Answer 3

As venous return increases, cardiac output to the systemic circulation will increase

Question 4

Increase in venous output will also distend the

Answer 4

Sinus nose

Question 5

If sinus node is distended, by how much will the heart rate increase

Answer 5

10-15%

Question 6

Venous return equation

Answer 6

VR = (Venous pressure - Right atrial pressure) / Venous resistance

Question 7

Decrease in right atrial pressure will lead to

Answer 7

An increase in venous output

Question 8

Increase in RA pressure effects on CO (Cardiac Output), VR (Venous return) and HR (Heart rate)

Answer 8

Decreased venous return
Decreased cardiac output
Decreased heart rate

Question 9

Normal values of venous return

Answer 9

5L

Question 10

Cardiac index during childhood and rest of life

Answer 10

Increases during childhood and decreases during adulthood

Question 11

Will an increase in venous return result in a better emptying of excess blood

Answer 11

Yes

Question 12

When does the heart become a limiting factor

Answer 12

When venous return&raquo_space; pumping capacity

Question 13

Heart rate when breathing in

Answer 13

Increases due to increased pressure in right atrium

Question 14

What occurs with postload in hypoeffective heart

Answer 14

Increases –> high blood pressure

Question 15

In volume-pressure diagram, Point 1 equals to

Answer 15

Closing of mitral valve

Question 16

Phase B equals to

Answer 16

Isovolumetric contraction as ventricle contracts but aortic valve not opened since P of ventricle is not yet greater than P aorta

Question 17

Point 2

Answer 17

Aortic valve opens

Question 18

Phase C

Answer 18

Decrease in ventricular volume as blood is ejected, pressure in left ventricle decreases

Question 19

Point 3

Answer 19

Aortic valve closed as Aortic pressure > ventricle pressure

Question 20

Phase D

Answer 20

Isovolumetric relaxation since aortic valve closed and there is no change in volume

Question 21

Point 4

Answer 21

Mitral valve opens because Pressure of right atria > pressure of right ventricle

Question 22

Phase A

Answer 22

blood flow from atrium to ventricle

Ventricle volume increases with slight increase in left ventricular pressure

Question 23

If preload increases where will the square shift

Answer 23

Right as there is more volume

Question 24

If preload increases where will the square shift

Answer 24

Right as there is more volume

Question 25

If contractility increases where will a shift occur

Answer 25

Left and up as pressure increases