Mechanism of Peristalsis in the Gut

Peristalsis is a reflex response. Initiated when the gut wall is stimulated by a stretch.

Oesophagus → Rectum. Law of Peristalsis, - Contraction of smooth muscles as a ring to the Oral/

retrograde direction from stimulus. - Relaxation of smooth muscles to the aboral/ anterograde

direction from stimulus. Stimuli from lumen are, - Stretching – detected by stretch receptors.

- Chemical stimulus - detected by mucosa. • Stretch receptors release → Serotonin • Which activates

sensory neurons that in turn activate the myenteric plexus. • Myenteric plexus has an,

- Ascending network of neurons → Retrograde direction - & a descending network of neurons → Anterograde

direction • For peristalsis to take place, - Ascending network of Cholinergic fibers