venous return is the return of blood to the right side of the heart via vena cava.
70% of blood is contained in veins at rest.
starlings law
during exercise, venous return increases. this causes more blood to be pumped back to heart therefore more needs to be pumped out, this will increase stroke volume
what 3 main mechanisms help blood in the large veins return to the heart?
skeletal muscle pump
respiratory pump
pocket valves
skeletal muscle pump.
musclescontracting change shape
this presses on nearby veins causing a pumping effect
