Question

Bicuspid and tricuspid valves are open during

• A. Ventricular systole
• B. Joint diastole
• C. Atrial systole
• D. Both (B) and (C)

Answer 1

The correct option is D

Both (B) and (C)

The correct option is D.

Explanation of correct option:

1. The bicuspid or left atrioventricular valve is located between the left atrium and the left ventricle of the heart. It has two cusps.
2. The tricuspid or right atrioventricular valve is located between the right atrium and the right ventricle. It has three cusps.
3. The relaxation of the heart chambers after contraction is known as diastole. Joint diastole is characterized by the relaxation of the atria and ventricles.
4. In atrial systole, both the atria contract simultaneously, and the blood pass into the ventricles which are in a relaxed state.
5. Bicuspid and tricuspid valves are open during both joint diastole and atrial systole. The opening of atrioventricular valves allows the blood to flow from the atria to the ventricles.

Explanation of incorrect option:

Option A:

1. Semilunar valves are open during ventricular systole, forcing the blood to flow into the pulmonary artery.
2. Bicuspid and tricuspid valves get closed at the beginning of ventricular systole.

Option B:

During joint diastole, bicuspid and tricuspid valves get opened.

Option C:

Bicuspid and tricuspid valves get opened during atrial systole.

Final answer: Bicuspid and tricuspid valves are open during both joint diastole and atrial systole.