Question

Venous return of blood to the heart depends on which of the following mechanisms?

1) Contraction of skeletal muscles
2) Respiratory pump
3) Venous valves
4) Sympathetic nervous system
5) All of the above

Answer 1

Venous return of blood to the heart depends on contraction of skeletal muscles, respiratory pump, venous valves, and the sympathetic nervous system.

Step-by-step explanation:

Venous return of blood to the heart depends on several mechanisms, including contraction of skeletal muscles, respiratory pump, venous valves, and the sympathetic nervous system.

Contraction of skeletal muscles, especially in the legs, helps increase the pressure in the veins and pushes blood upward toward the heart. The respiratory pump, which occurs during inhalation and exhalation, also plays a role in venous return by creating pressure changes in the chest and abdomen that assist in blood flow.

Additionally, the presence of venous valves prevents backflow of blood in the veins, while the sympathetic nervous system helps regulate blood vessel constriction and dilation to maintain appropriate blood flow.