name the type of muscles that accomplish peristalsis
Peristalsis In much of a digestive tract such as the human gastrointestinal tract, smooth muscle tissue contracts in sequence to produce a peristaltic wave, which propels a ball of food (called a bolus while in the esophagus and upper gastrointestinal tract and chyme in the stomach) along the tract. Peristaltic movement comprises relaxation of circular smooth muscles, then their contraction behind the chewed material to keep it from moving backward, then longitudinal contraction to push it forward.
Gastrocnemius muscle In humans, the gastrocnemius muscle (/ˌɡæstrɒkˈniːmiəs/ or /ˌɡæstrəkˈniːmiəs/; plural gastrocnemii; Latin, from Greek γαστήρ "stomach" and κνήμη (knḗmē) "leg"; meaning "stomach of leg" (referring to the bulging shape of the calf) is a very powerful superficial bipennate muscle that is in the back part of the lower leg. It runs from its two heads just above the knee to the heel, a two joint muscle.