Anatomy and Physiology II Practice Test

Which valve opens to allow blood to flow from the right ventricle into the pulmonary artery?

1. Aortic valve

2. Tricuspid valve

3. Pulmonary semilunar valve

4. Mitral valve

The correct answer is: Pulmonary semilunar valve

The valve that opens to allow blood to flow from the right ventricle into the pulmonary artery is the pulmonary semilunar valve. During the cardiac cycle, when the right ventricle contracts, it generates pressure that forces the valve open, permitting deoxygenated blood to exit the heart and travel through the pulmonary artery to the lungs. In the lungs, this blood receives oxygen and releases carbon dioxide, making the function of the pulmonary semilunar valve essential for proper respiratory and circulatory function. The other valves play different roles in the heart's function. The aortic valve, for example, is responsible for regulating blood flow from the left ventricle to the aorta. The tricuspid valve is located between the right atrium and right ventricle, controlling blood flow into the ventricle from the atrium. The mitral valve serves a similar purpose but is located on the left side, between the left atrium and left ventricle. Each valve has a distinct role, but in the context of blood flow from the right ventricle to the pulmonary artery, the pulmonary semilunar valve is the key structure involved.