Question

18. Which one of the following is a matching pair?

1) Lub - sharp closure of AV valves at the beginning of ventricular systole

2) Dub-sudden opening of semilunar valves at the beginning of ventricular diastole

3) Pulsation of the radial artery-valves in the blood vessels

4) Initiation of heart beat-purkinje fibres​

Answer 1

Answer:

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Explanation:

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