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Created page with '==The Vomit Reflex== right|thumb|150px|The Vomit Reflex - Copyright nabrown RVC *Emesis is the process of vomiting *Persistent vomiting ca…'
==The Vomit Reflex==
[[Image:The Vomit Reflex Pathway.jpg|right|thumb|150px|The Vomit Reflex - Copyright nabrown RVC]]
*Emesis is the process of vomiting
*Persistent vomiting can be exhausting and can lead to metabolic alkalosis, dehydration and electrolyte inbalances which may require fluid therapy
*Extreme cases of persistent vomiting can lead to shock
*Retching involves the abdominal and chest walls contracting
*Vomiting includes retching and the action of the diaphragm
*Diaphragm moves caudal to open the cardia
*Gastrointestinal tract have protective stimuli to recognise harmful products ingested. The mechanoreceptors and chemoreceptors respond using viscerent afferent pathways.
*Medulla co-ordinates process
*Chemoreceptive trigger zone in the 4th ventricle responds to blood and CSF
*Inputs also from inner ear and higher centres
*Emetic agents can be used in cases of gastric obstruction and to remove non-corrosive poisons from the stomach (for corrosive poisons charcoal can be used which will help adsorb the substance and decrease its absorbtion into the GIT)
*For more information on emetic and anti-emetic drugs click [[Emetics and Anti-Emetic Drugs|here]]
===Emetic agents===
*Drugs cause emesis by irritating the gastric mucosa
**Histamine
**ACh
**Dopamine
**Catecholamines
**5-hydroxytryptamine
**Substance P
**Enkephalins
**NK1 receptor agonists
===Anti-emetic agents===
*Anti-emetic agents can be used to treat motion sickness and to treat or prevent vomiting
**Dopamine (D2) receptor antagonists
**5-hydroxytryptamine antagonists
**NK1 receptor antagonists
**Muscarinic receptor antagonists
**Histamine (H1) receptor antagonists
**Gastroprotective agents
[[Image:The Vomit Reflex Pathway.jpg|right|thumb|150px|The Vomit Reflex - Copyright nabrown RVC]]
*Emesis is the process of vomiting
*Persistent vomiting can be exhausting and can lead to metabolic alkalosis, dehydration and electrolyte inbalances which may require fluid therapy
*Extreme cases of persistent vomiting can lead to shock
*Retching involves the abdominal and chest walls contracting
*Vomiting includes retching and the action of the diaphragm
*Diaphragm moves caudal to open the cardia
*Gastrointestinal tract have protective stimuli to recognise harmful products ingested. The mechanoreceptors and chemoreceptors respond using viscerent afferent pathways.
*Medulla co-ordinates process
*Chemoreceptive trigger zone in the 4th ventricle responds to blood and CSF
*Inputs also from inner ear and higher centres
*Emetic agents can be used in cases of gastric obstruction and to remove non-corrosive poisons from the stomach (for corrosive poisons charcoal can be used which will help adsorb the substance and decrease its absorbtion into the GIT)
*For more information on emetic and anti-emetic drugs click [[Emetics and Anti-Emetic Drugs|here]]
===Emetic agents===
*Drugs cause emesis by irritating the gastric mucosa
**Histamine
**ACh
**Dopamine
**Catecholamines
**5-hydroxytryptamine
**Substance P
**Enkephalins
**NK1 receptor agonists
===Anti-emetic agents===
*Anti-emetic agents can be used to treat motion sickness and to treat or prevent vomiting
**Dopamine (D2) receptor antagonists
**5-hydroxytryptamine antagonists
**NK1 receptor antagonists
**Muscarinic receptor antagonists
**Histamine (H1) receptor antagonists
**Gastroprotective agents