Venous Return during exercise

Question 1

What are problem 1&2?

Answer 1

1) The blood pressure of the veins which returns blood to the heart=0
2) most of the cardiac output is found in the legs so must travel against gravity to return to the heart

Question 2

What are the 5 solutions?

Answer 2

1) pocket valves
2) skeletal muscle pump
3) smooth muscle
4) respiratory pump
5) gravity from above the heart

Question 3

What are pocket valves?

Answer 3

In larger veins that prevent the back flow of blood

Question 4

What are skeletal muscle pumps?

Answer 4

When the lower leg muscles contract, they get wider and press again the vein wall, squeezing blood up towards the heart

Question 5

What are the smooth muscles?

Answer 5

A thin layer of muscle of smooth muscle in the vein walls which allows venoconstriction to move blood up towards the heart

Question 6

What is the respiratory pump?

Answer 6

When inhaling, the diaphragm flattens, decreasing volume and increasing pressure in the abdominal to below the pressure in the thoracic cavity. This pressure differential pulls blood up towards the heart

Question 7

What is the gravity from the heart?

Answer 7

Helps blood returning to the heart from the upper body