Question

The valve which prevents back flow of blood in the veins is _______________

• A. Tricuspid valve
• B. Mitral valve
• C. Semilunar valve

Answer 1

The correct option is C

Semilunar valve

The correct option is C.

Explanation of the correct option:

1. Veins carry blood towards the heart from various organs of the body.
2. Semilunar valves are present in veins.
3. The main function of the valves in veins is to prevent back flow of blood.
4. Blood in the arteries, after being pumped by the heart, are under much higher pressure than blood in veins so there is no need for valves in arteries to prevent back flow.
5. Blood in veins is under much lower pressure as it is returning to the heart from the various organs and tissues and so has a risk of back flow if the valves are not present to prevent it.
6. Valves also help blood travel back to the heart against the force of gravity.

Explanation of the incorrect option:

Option A:

1. Tricuspid valve is located between the right atrium and the right ventricle.
2. It prevents the back flow of blood from right ventricle to right atrium during ventricular systole.

Option B:

1. The mitral valve also known as bicuspid valve is located in the left side of the heart, between the left atrium and left ventricle.
2. It prevents the back flow of blood from left ventricle to left atrium during ventricular systole.

Final answer:The valve which prevents back flow of blood in the veins is Semilunar valve.