Question

Rate of heartbeat is determined by

• A. SA node
• B. AV node
• C. Purkinje fibres
• D. Papillary muscles

Answer 1

The correct option is A

SA node

The correct option is (A)

Explanation of the correct option:

SA node determines the rate of the heartbeat as impulse starts in a small bundle of these specialized cells only.

Explanation of the incorrect options:

Option (B)

AV node is a cluster of cells that acts like a gate that slows the electrical signal before it enters the ventricles.

Option (C)

Purkinje fibers force blood out of the heart to our lungs and body.

Option(D)

Papillary muscles prevent leakage of blood through the AV valves during systole.

Final answer: The rate of heartbeat is determined by the SA node.