Peristalsis

Peristalsis is a radially symmetrical contraction and relaxation (which is expansion) of muscles that propagates in a wave down a tube, in an anterograde direction. Peristalsis is progression of coordinated contraction of involuntary circular muscles, which is preceded by a simultaneous contraction of the longitudinal muscle and relaxation of the circular muscle in the lining of the gut. Earthworms use a similar mechanism to drive their locomotion, and some modern machinery imitate this design.

Peristalsis

Peristalsis is a radially symmetrical contraction and relaxation (which is expansion) of muscles that propagates in a wave down a tube, in an anterograde direction. Peristalsis is progression of coordinated contraction of involuntary circular muscles, which is preceded by a simultaneous contraction of the longitudinal muscle and relaxation of the circular muscle in the lining of the gut. Earthworms use a similar mechanism to drive their locomotion, and some modern machinery imitate this design.