PHGY 210 Lecture Notes - Lecture 13: Rectum, Peristalsis, Disorganized Schizophrenia
Document Summary
> emptying of contents of upper git results *reverse flow of contents. Cause = action of diaphragm & abdominal muscles to increase intra-abdominal pressure. *git = mostly passive - only duodenum si & distal portion of stomach = in spasm. Contraction of duodenum & stomach contraction diaphragm & intra-abdominal muscles. Every sphincter relaxed -> contents moved because of high intra-abdominal pressure. > complex /highly coordinated reflexes-> initiated by wide variety of factors. Afferent= pharyngeal stimulation (finger in throat/physical st) / gi or upper gi distension / irritation / Inflammation/ cardiac ischemia / pain/ chemical disequilibrium (motion sickness-vestibular) / unequal. Efferent = widespread autonomic discharge & nausea -> retching -> Increased salivation to protect from low ph vomit. Vomiting centre=if removed - won"t be able to vomit no matter how much/how strong stimulus. * need brain centre/necessary for vomitting -> activation of parasympathetic & sympathetic activities. 1- relaxation of upper gi tract & spasm of pyloric antrum & duodenum.
