In peristalsis following are involved except ?
Ans. is 'c' i.e., Noradrenaline Peristalsis requires an active myenteric (Auerbach's) plexus. Local stretch by chyme releases serotonin, which activates myenteric plexus. Cholinergic neurons of this plexus passing in a retrograde direction release substance P and acetylcholine, causing smooth muscle contraction. Cholinergic neurons passing in an antegrade direction activate neurons that secrete NO, VIP, and ATP, produing relaxation ahead of the stimulus.
NO
Substance P
Noradrenaline
VIP