Question:
Consider the following statements:
Assertion (A): Heart of human beings is myogenic.
Reason (R): Pace maker in human beings is formed by modified cardiac muscles.
Consider the following statements:
Assertion (A): Heart of human beings is myogenic.
Reason (R): Pace maker in human beings is formed by modified cardiac muscles.
Show Hint
The SA node is the natural pacemaker of the human heart and consists of modified cardiac muscle fibres that initiate heartbeat.
Updated On: Jun 12, 2026
- Both (A) and (R) are correct, (R) is the correct explanation of (A)
- Both (A) and (R) are correct, (R) is not the correct explanation of (A)
- (A) is correct, but (R) is not correct
- (A) is not correct, but (R) is correct
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Verified By Collegedunia
The Correct Option is A
Solution and Explanation
Concept:
A heart is called myogenic when the impulse initiating contraction originates within the cardiac muscle itself rather than from nervous stimulation.
Human heart exhibits myogenic activity.
Step 1: Analyze the Assertion. In human beings, heartbeat originates within the heart. The impulse is generated by specialized cardiac tissue. Therefore the human heart is myogenic. Thus Assertion (A) is true.
Step 2: Analyze the Reason. The sinoatrial (SA) node acts as the natural pacemaker of the heart. The SA node consists of modified cardiac muscle fibres capable of generating rhythmic electrical impulses. Therefore Reason (R) is also true.
Step 3: Determine the relationship. Since impulses arise from modified cardiac muscle cells of the SA node, the heart can initiate contractions independently. This directly explains why the heart is myogenic.
Step 4: Final conclusion. Both statements are true and the Reason correctly explains the Assertion. \[ \boxed{\text{Both true and Reason correctly explains Assertion}} \] Hence option (A) is correct.
Step 1: Analyze the Assertion. In human beings, heartbeat originates within the heart. The impulse is generated by specialized cardiac tissue. Therefore the human heart is myogenic. Thus Assertion (A) is true.
Step 2: Analyze the Reason. The sinoatrial (SA) node acts as the natural pacemaker of the heart. The SA node consists of modified cardiac muscle fibres capable of generating rhythmic electrical impulses. Therefore Reason (R) is also true.
Step 3: Determine the relationship. Since impulses arise from modified cardiac muscle cells of the SA node, the heart can initiate contractions independently. This directly explains why the heart is myogenic.
Step 4: Final conclusion. Both statements are true and the Reason correctly explains the Assertion. \[ \boxed{\text{Both true and Reason correctly explains Assertion}} \] Hence option (A) is correct.
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