Zoology-Heart & Circulation

NEET Zoology Heart & Circulation MCQ Question

Type: MCQ-conceptual-Medium-Class 11

Which of the following statements about the heart's electrical activity and structure is correct?

A

The sino-atrial node initiates the heartbeat and is located in the right atrium.

B

The atrioventricular node is responsible for initiating the contraction of the atria.

C

The cardiac muscle is primarily composed of skeletal muscle fibers.

D

The valves of the heart allow blood to flow in both directions between the chambers.

Correct Answer

Option A

Detailed Explanation

The sino-atrial node (SAN) is indeed located in the right atrium and is responsible for initiating the heartbeat, as mentioned in the NCERT context. The other statements are incorrect based on the structure and function of the heart.

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