Answer to Question #154636 in Human Anatomy and Physiology for Malak Rostom

Question

During the bypass surgery for coronary heart disease patient, can the surgeon remove the semi-lunar valves of the vein taken from the leg or it must be inserted with the semi-lunar valves with care to prevent that valves become against the blood flow direction

Answer 1

The aortic semilunar valve and pulmonary semilunar valve prevent blood from flowing back into the chambers. These valves contract to prevent blood from flowing back into the atria, and relax to prevent blood from flowing back into the ventricle. During the bypass surgery, semi-lunar valves of the vein taken from the leg must be inserted with care to prevent that valves from becoming against the blood flow direction.