Vomiting
Forceful expulsion of gastrointestinal content is vomiting. There should be antiperistalsis movement and content should move opposite direction.
Vomiting results from squeezing of abdominal muscle with sudden opening of oesophageal sphincters.
Vomiting is regulated by vomiting centre located in the brain. There are some sequent of event. First take deep breathe and rising of hyoid bone at larynx to pull open the upper oesophageal sphincter. Then closing of glottis and letting soft palate to close nostrils. Abdominal muscles and diaphragm contact and pressure cause opening of lower oesophageal sphincter.