The purpose of the aortic valve is to prevent blood from flowing backward into the heart.

Thick heart muscle prevents blood from filling the left ventricle.

The sheath had a valve to prevent blood from escaping.

A: The valves in the venous system are designed to prevent blood from traveling backward down the legs.

These valves prevent blood from flowing back into the ventricles.

These help prevent blood from pooling in your legs.

It is an inherited disease that prevents blood from clotting.

To solve this problem, the skin of the lower legs is thick and tight; preventing too much blood from pouring into them.

It has valves within it that prevent blood from flowing the wrong way.

This is to prevent blood and plasma from becoming common commodities.