18 Feb 2016 | 258,249 Views. You may not even associate this with your health, yet it can make a life or death difference. Ignore or defy it, and your risk of death before your 65th birthday jumps 25 percent. Here's the big takeaway message to tell your body for health and longevity.
1 Veins have valves which maintain the unidirectional flow of blood, even against gravity. 2  Since the venous pressure is low (7 mm Hg) the valves are of utmost value in the venous return. However, the valves are absent in: 3  The veins of less than 2 mm diameter.  The venae cavae.
Left Ventricle â left inferior chamber of the heart that pumps oxygenated blood to the body. Right Ventricle â left inferior chamber of the heart that pumps oxygen-poor blood to the lungs. 5. Name the heart valves and describe their location, function, and mechanism of operation..Ventricular systole: the ventricles contract and pump blood out of the heart into the arteries. During this stage the atrioventricular valves are closed and the semilunar valves are open. This takes about 0.3 second. The total cycle takes about 0.8 second while the subject is resting.