Which cells are referred as “Pacemaker cells” with
relation to ‘BER’?
a) SA node
b) AV node
c) Interstitial cells of Cajal.
d) Pyramidal cells
Correct Answer - C
Interstitial cells of Cajal
Basic Electrical Rhythm (BER):
Smooth muscle cells of the gastrointestinal tract have spontaneous
rhythmic fluctuations in membrane potential between about -65 and
-45 mV.
BER initiated by Pacemaker cells called “Interstitial cells of Cajal”.
Pacemaker cells -
Interstitial cells of Cajal.
Stellate mesenchymal cells with smooth muscle-like features.
Location:
Are absent in esophagus & proximal stomach.
In distal stomach & small intestine - Located in outer circular muscle
layer near myenteric plexus.
In colon - Located at the submucosal border of circular muscle layer.
Frequency:
In Stomach & small intestine -
Pacemaker frequency is in descending gradient.
Pacemaker with the highest frequency usually dominates (Eg., In
Heart)