What happens when the pacemaker becomes non-functional?
-
Only auricles contract rhythmically
-
Only ventricles contract rhythmically
-
Cardiac muscles do not undergo coordinated rhythmic movements
-
Cardiac muscles contract in coordinated manner rhythmically
-
Auricles and ventricles contract rhythmically.
Reveal answer
Fill a bubble to check yourself
C
Correct answer
Explanation
The natural (SA node) or artificial pacemaker has a function to send electrical impulses from atrium for contraction and pumping action into the ventricles. The impulses get transferred in the following route :
SA node(pacemaker) $\rightarrow$ Interatrial cardiac fibre $\rightarrow$ AV node(pacesetter) $\rightarrow$ Bundle of his $\rightarrow$ Bundle branch $\rightarrow$Purkinje fibres.
Thus, the rhythmic contraction of the heart is made by SA node.
So, if the pacemaker becomes non-functional then, cardiac muscles do not undergo coordinated rhythmic movement.