Which one of the following is a matching pair ?

Options

A. Lubb-Sharp closure of AV valves at the beginning of ventricular systole
B. Dub-Sudden opening of semilunar valves at the beginning of ventricular diastole
C. Pulsation of the radial artery-valves in the blood vessels
D. Initiation of the heart beat-Purkinje fibres

Answer

To solve the question of which one of the following is a matching pair, we will analyze each option provided:

1. **Option A: Lubb, sharp closure of AV valves at the beginning of ventricular systole.**
- The first heart sound, known as "Lubb," is indeed produced by the closure of the atrioventricular (AV) valves (which include the mitral and tricuspid valves) at the start of ventricular contraction (systole). This statement is correct.

2. **Option B: Dubb, sudden opening of semilunar valve at the beginning of ventricular diastole.**
- The second heart sound, "Dubb," is produced by the closure of the semilunar valves (aortic and pulmonary valves) at the end of ventricular systole, not the opening at the beginning of diastole. This statement is incorrect.

3. **Option C: Pulsation of radial artery valves in the blood vessel.**
- The pulsation of the radial artery is not caused by valves but rather by the pressure wave generated when the heart pumps blood into the arteries. Therefore, this statement is also incorrect.

4. **Option D: Initiation of the heartbeat per Purkinje fibers.**
- The initiation of the heartbeat is primarily controlled by the sinoatrial (SA) node, not the Purkinje fibers. The Purkinje fibers are responsible for conducting the impulse throughout the ventricles after it has been initiated by the SA node. Thus, this statement is incorrect.

Based on the analysis, the only correct matching pair is:

**Correct Answer: Option A - Lubb, sharp closure of AV valves at the beginning of ventricular systole.**