what type of contraction is Peristalsis
Peristalsis is a distinctive pattern of smooth muscle contractions that propels foodstuffs distally through the esophagus and intestines. One group of interneurons activates excitatory motor neurons above the bolus-these neurons, which contain acetylcholine and substance P, stimulate contraction of smooth muscle above the bolus. 2  Another group of interneurons activates inhibitory motor neurons that stimulate relaxation of smooth muscle below the bolus.