Question

A person consumes alcohol and sometime later he experiences nausea, bloating and eventually vomits. takes place in such cases resulting in vomiting.

• A. nutrient absorption
• B. reverse osmosis
• C. reverse peristalsis
• D. gut contraction

Answer 1

The correct option is C reverse peristalsis

Vomiting is a protective mechanism that helps purge the gastro-intestinal system of harmful substances, barring further entry of such substances into the rest of the body. Stomach senses the presence of irritants in the consumed food and sends a signal to the vomiting centre of the brain stem. Vomiting centre triggers the vomiting reflex and initiates reverse peristalsis in small intestine. Food starts moving back to the stomach. Pylorus relaxes to receive the backflow of food. Deep breath is taken involuntarily and this increases the gastric pressure which forces the content upwards. Lower oesophageal sphincter relaxes, allowing the entry of the gastric contents into the oesophagus. Forceful expulsion of the gastric and duodenal contents occurs throught the mouth. This is a mechanism by which digestive system maintains homeostasis by eliminating harmful substances.