Which of the following have maximum Post prandial contractibility: (AIIMS MAY 2011, NOV 2008)
I. GI Motility is due to some cells in the smooth muscle of GI mucosa called as interstitial cell of cajal which generate basic electrical rhythm (BER) and act as a pacemaker and regulate the motility.
II. These BERs rarely cause muscle contraction but spike potential superimposed on the most depolarizing portion increases muscle tension.
III. Acetyl choline increase the no. of spikes and tension developed in smooth muscles, hence increases motility.
Rate of BER is:
a. 4/min in stomach b. 12/min in duodenum
c. 8/min in distal ileum d. 9/ min in caecum
e. 16/min in sigmoid colon
so, maximum motility develops in sigmoid colon.