Venous Return Flashcards
Name the 5 mechanisms involved in venous return
Skeletal Muscle Pump
Pocket Valves
Smooth Muscle
Respiratory Pump
Gravity
What does Starling’s Law state?
Venous return = stroke volume
How does the skeletal muscle pump work?
Repeated muscle contractions squeeze and compress blood through the veins and back to the heart
Why do athletes do an active cool down?
This ensures that high amounts blood is still returned back to the heart despite fewer and less frequent muscle contractions
How do pocket valves work?
As the blood is forced up through the vein,pocket valves form a closure which prevents the back flow of blood
How does smooth muscle work?
It surrounds the valves and contracts and constricts,helping pump blood upwards through the valves and veins back to the heart
How does the respiratory pump work?
Constant breathing in and out causes continuous changes in thoracic pressure which itself squeezes blood back to heart
How does gravity work in venous return?
When blood is pushed out to places above the heart (heads/arms) gravity pulls the blood back down and back to the heart
This is the reason why athletes often lay on their back and raise their legs upwards after exercise
What is the primary purpose of the venous return mechanisms?
Increase the amount of blood that returns back to the heart
