Vomiting centre

Vomiting refers to the forceful expulsion of contents from stomach and intestine. Vomiting centre is situated in the reticular formation of medulla oblongata near the vagal nucleus. Vomiting may be initiated by either activation of vomiting centre or by an activation of the chemoreceptor trigger zone. It may be activated directly or through afferents: Direct activation of the vomiting centre Afferent impulses activating vomiting centre. Sequence of mechanical events of vomiting: Pre-ejection phase Retching phase Ejection phase. Ref: guyton and hall textbook of medical physiology 12 edition page number:442,443,444