Emesis receptor is -

Ans. is 'c' i.e., 5HT3 Vomiting centre and nucleus of tractus solitarius contain muscarinic, cholinergic and histamine H, receptors. CTZ is located in area postrema (outside BBB) and contains Dopamine D2, opioid & serotonine 5-HT3 receptors. o So, antiemetic that act on vomiting centre have antimuscarinic and antihistaminic action --> can allete vomiting from any cause. o Drugs acting on CTZ have Dopamine D, antagonistic and 5-HT3 antagonistic action --> effective only in vomiting mediated by stimulation of chemoreceptors (by morphine, cytotoxic drugs, digoxin).