oesophagus has special peristaltic movements ..give reason
Answers
Answer:
Peristaltic movement of digestive system helps the food to move downwards from mouth to the stomach through oesophagus. It moves the food in a wave like manner by a rhythmic contraction and relaxation of the muscles present in the walls of oesophagus.
Explanation:
Peristalsis is a radially symmetrical contraction and relaxation of muscles that propagates in a wave down a tube, in an anterograde direction.
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.
Earthworms use a similar mechanism to drive their locomotion,and some modern machinery imitates this design.
The word comes from New Latin and is derived from the Greek peristellein, "to wrap around," from peri-, "around" + stellein, "draw in, bring together; set in order"