Vomiting Flashcards
What is the definition of vomiting?
The expulsion of gastric contents and sometimes proximal duodenal contents back into the oral cavity.
What might one benefit of vomiting be?
Protecting the individual from ingestion of noxious substance
What are the 3 stages of vomiting?
1) Nausea = precedes retching and vomiting
2) Retching = forceful contractions of the abdominal muscles and diaphragm forcing gastric contents into the oesophagus
3) Vomiting = occurs as the gastric contents are forcefully expelled out of the mouth.
What is the method by which vomiting occurs?
1) Deep inspiration and simultaneous closure of the glottis and nasal cavities
2) Forceful contractions of the abdominal muscles
3) Large increased pressure in the abdominal cavity which is transferred to contents of the stomach
4) Cardiac sphincter opens and gastric contents expelled into the oesophagus
5) Upper oesophageal sphincter opens
6) Contents expelled through the mouth.
How is vomiting regulated?
Vomiting is regulated by the vomiting centre within the medulla oblongata.
What is the chemoreceptor trigger zone (CTZ) and where is it located?
It is located in the floor of the fourth ventricle of the brain. The CTZ contains receptors that detect emetic agents in the blood and CSF and relays information to the vomiting centre.
