MEDICAL PHYSIOLOGY

Detailed explanation-1: -Vomiting is believed to be controlled by two distinct brain centres-the vomiting centre and the chemoreceptor trigger zone-both located in the medulla oblongata. The vomiting centre initiates and controls the act of emesis, which involves a series of contractions of the smooth muscles lining the digestive tract.

Detailed explanation-2: -"Motility” is an unfamiliar word to many people; it is used primarily to describe the contraction of the muscles in the gastrointestinal tract. Because the gastrointestinal tract is a circular tube, when these muscles contract, they close off the tube or make the opening inside smaller-they squeeze.

Detailed explanation-3: -Vomiting can serve the function of emptying a noxious chemical from the gut, and nausea appears to play a role in a conditioned response to avoid ingestion of offending substances.