NEET 2003 · Class 11

Body Fluids and Circulation

The cardiac pacemaker in a patient fails to function normally. The doctors find that an artificial pacemaker is to be grafted in him. It is likely that it will be grafted at the site of

  1. (A)atrioventricular bundle
  2. (B)Purkinje system
  3. (C)sinuatrial node
  4. (D)atrioventricular node

The NCERT line that answers it

Verbatim line

The SAN can generate the maximum number of action potentials, i.e., $70-75 \text{ min}^{-1}$ , and is responsible for initiating and maintaining the rhythmic contractile activity of the heart.

Chapter
Body Fluids and Circulation
Section
15.3.1 Human Circulatory System
Page
6
Words matched
6 of 6

The answer appears as a continuous sentence in NCERT. This is that sentence.

How this line gives the answer

6, emb=1.0, combined=0.84). Verified: high — The span explicitly states that the SAN is responsible for initiating and maintaining the rhythmic contractile activity of the heart, which directly explains why it is the natural pacemaker and would be replaced by an artificial one.

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