Answer:
The heart valves prevent the backward flow of blood.
The aortic valve is located between the left ventricle and the aorta.
After the left ventricle contracts, the aortic valve closes and the mitral valve opens, to allow blood to flow from the left atrium into the left ventricle.
Each valve actually has three flaps, except the mitral valve, which has two flaps.
Step-by-step explanation:
The heart valves prevent the backward flow of blood.
The aortic valve is located between the left ventricle and the aorta.
After the left ventricle contracts, the aortic valve closes and the mitral valve opens, to allow blood to flow from the left atrium into the left ventricle.
Each valve actually has three flaps, except the mitral valve, which has two flaps.