HTHSCI 2H03 Lecture Notes - Lecture 22: Vasodilation, Domperidone, Efferent Nerve Fiber

• School: McMaster University
• Department: Health Sciences
• Course: HTHSCI 2H03
• Professor: kirsten

Document Summary

Vomiting: forceful expulsion of stomach contents and the contents of the proximal small intestine: associated with many conditions- it is a symptom not a disease. Highly sequenced and tightly controlled biological response: nausea, et(cid:272)hi(cid:374)g (cid:894)(cid:858)dr(cid:455) hea(cid:448)es(cid:859)(cid:895, vomiting (cid:858)proje(cid:272)tile vo(cid:373)iti(cid:374)g(cid:859) Regurgitation: return of previously swallowed food or secretions into the mouth (involuntary) Rumination: repetitive, effortless regurgitation of recently ingested food into the mouth followed by re- chewing and re-swallowing (voluntary, purposeful) Nausea: a(cid:374) u(cid:374)pleasa(cid:374)t a(cid:374)d diffi(cid:272)ult to des(cid:272)ri(cid:271)e (cid:862)ps(cid:455)(cid:272)hi(cid:272)(cid:863) e(cid:454)perie(cid:374)(cid:272)e, sensation of unease and discomfort. Physiologically, nausea is asso(cid:272)iated (cid:449)ith : decreased gastric motility. Increased small intestinal tone: reverse proximal small intestinal peristalsis. Diaphragm contracts, pushes down on the stomach and forces the contents up the esophagus. A complex, stereotypical, set of activities that leads to vomiting. Three anatomically and functionally distinct units that control vomiting: vomiting centres (vc, nucleus tractus solitarius (nts, chemoreceptor trigger zones (ctz) Bilateral vomiting centres: found in the reticular formation of the medulla.