Right at the very start of the aorta is the aortic valve and at the very start of the pulmonary artery is the pulmonart valve, each of which are semilunar. In the heart there are two semilunar valves that lad to blood vessels. The pulmonary semilunar valve leads to the pulmonary trunk, and the Aortic semilunar valve leads to the Aorta.
Veins and lymphatic vessels have valves.
Only veins contain valves. The valves prevent the backward flow of blood.
Valves are in the veins.
Semilunar valves are open when the blood is being pumped. The AV valves are closed when the semilunar valves are open.
The heart does not have doors, but it does have valves that could be thought of as doors. They consist of the semilunar valves (the pulmonary semilunar valve and the aortic semilunar valve). The other two are the atrioventricularvalves (tricuspid and bicuspid valves).
Blood is ejected from the ventricles into the major blood vessels that are connected to the heart: the aorta on the left side and the pulmonary trunk on the right side
Veins
The semilunar valves are open when blood is being pumped by ventricular contraction. This event is called systole.
the function of the semilunar valves are that they provied the lungs with glucose and oxygen.
The only blood vessels that contain valves are veins.
Semilunar valves
There are two semilunar valves, one is located at the top of the right side of the heart, just before the pulmonary trunk leading to the pulmonary arteries, the other is located at the top of the left side of the heart, just before the aorta. They both prevent backflow of blood to the heart.
Damage to the left semilunar valve would interfere with blood flow to the aorta.