Question
Question: What is peristalsis?...
What is peristalsis?
Solution
Many invertebrates, including caterpillars, millipedes, and Earthworms, use this common mechanism of involuntary motion to drive their locomotion.
Complete answer:
The term "peristalsis" derives from New Latin and comes from the Greek peristellein, "to attach or draw, to bring together or to place in order." Peristalsis is a series of wave-like muscle contractions, which move food to various digestive tract processing stations. Peristalsis occurs at the oesophagus when a food particle is consumed. The smooth muscle's powerful wave-like movements in the oesophagus bring the food to the stomach, where it is churned into a liquid mixture called chyme. Also, it begins in the small intestine, where it blends and moves the chyme back and forth, allowing nutrients to be absorbed through the small intestine walls into the bloodstream.
Bayliss and Starling first defined it as a form of motility in which there is contraction above and relaxation underneath a segment being stimulated. Vagotomy or sympathectomy does not affect it to any degree, suggesting its regulation by the central, intrinsic nervous system in the intestine. Peristalsis ends in the large intestine, where water is absorbed into the bloodstream from undigested food material. Lastly, the residual waste products are excreted into the rectum and anus from the body.
The earthworm is an annelid worm that lacks a limb, with a hydrostatic skeleton that passes by peristalsis. The hydrostatic skeleton consists of a body cavity filled with fluid surrounded by an extensible body wall. The worm pushes by radially constricting the anterior portion of its body, resulting in hydrostatic pressure increases in length. This restricted area later propagates around the body of the worm. As a result, each segment is stretched forward, then relaxes and contacts the substratum again, with a hair-like seat preventing slipping backward. Several other invertebrates also travel through peristalsis, such as caterpillars and millipedes.
Note: Peristalsis is a muscle tissue contraction, which helps to transfer and break down foods. These peristaltic waves transfer nutrients into the intestines and waste products are excreted into the rectum and anus from the body.