|
SA node is called the pacemaker of heart because |
|
|
a) |
It can change the contractile activity generated by AV node |
|
b) |
It delays the transmission of impulse between the atria and ventricles |
|
c) |
It gets stimulated when it receives neural signals |
|
d) |
It initiates and maintains the rhythmic contractile activity of heart |
|
SA node is called the pacemaker of heart because |
|
|
a) |
It can change the contractile activity generated by AV node |
|
b) |
It delays the transmission of impulse between the atria and ventricles |
|
c) |
It gets stimulated when it receives neural signals |
|
d) |
It initiates and maintains the rhythmic contractile activity of heart |
(d)
SA node is known as the pacemaker of heart because the cells in SA node contract the most number of times per minute and because each wave of excitation begins here and acts as the stimulus for the next wave of excitation. In a diseased heart, the AV node can act as a pacemaker though it beats at comparatively less frequency (around 40-50 per min)