Venous return and Starlings law

Question 1

Starlings law

Answer 1

the greater the venous return the greater the stroke volume is.
- as venous return increases the walls of the ventricles are stretched further which results in a more powerful contraction. it increases the amount of blood pumped around the body during exercise.

Question 2

Venous return

Answer 2

return of blood to the right hand side of the heart via the vena cava.

Question 3

5 ways venous return can occur

Answer 3

Gravity
Smooth muscle
Pocket valves
Skeletal muscle pump
Respiratory pump

Question 4

Gravity

Answer 4

help blood return to the heart.
- superior vena cava falls back to heart.

Question 5

Smooth muscle

Answer 5

a thin layer of smooth muscle in the veins helps squeeze blood back towards the heart.

Question 6

Pocket valves

Answer 6

• found in the veins
• as blood pushed upwards it will close and prevent back flow of blood.

Question 7

Skeletal muscle pump

Answer 7

veins run through the muscles and as the muscles work blood is squeezed allowing better venous return.

Question 8

Respiratory pump

Answer 8

when muscles contract and relax during the inspiration and expiration process, pressure changes occur in the thoracic and abdomen cavities.
- these pressure changes compress the nearby veins and assist blood return to the heart.