
- Vomiting or emesis is the forceful expulsion of gastric contents out through the mouth and generally perceived as being caused by abnormal gastric motility.
- Stomach, esophagus and associated sphincter relaxes during vomiting.
- The major force of expulsion comes from contraction of respiratory muscles (diaphragm and abdominal muscles which aid during active expiration)
- Vomiting is coordinated by Vomiting Center in medulla.
- It begins with a deep inspiration and closure of glottis to prevent vomited material enter respiratory passage and uvula is elevated to close the nasal cavity.
- The contracting diaphragm descends down on stomach and contraction of abdominal muscles compresses the abdominal cavity, increasing the intra-abdominal pressure and forcing the abdominal viscera upward.
- This would cause the gastric contents forced upward through the relaxed sphincter and esophagus and out through mouth
- Vomiting is usually preceded by profuse salivation, sweating, rapid heart beat, and sensation of nausea.
- Causes of Vomiting:
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- Tactile (touch) stimulation of the back of the throat
- Irritation or distention of stomach
- Elevated intracranial pressure from cerebral hemorrhage
- Rotation or acceleration of head
- Chemical Agents
- Emotional factors
- Effect of Vomiting
- Reduction of plasma volume can lead to dehydration and circulatory and loss of acid would lead to metabolic alkalosis
- Vomiting also beneficial in removing noxious material in stomach (emetics given in the case of accidental
ingestion of poison)

