PSL301H1 Lecture Notes - Lecture 30: Coeliac Disease, Gastric Pits, Gastric Glands
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PSL301H1 Full Course Notes
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Estimated of about 2l input of fluid into lumen and into gi tract. How is surface area increased? if gi tract is simple tube, then we can introduce folds, hills/valleys, and microscopic protrusions on each other. Degree of increase in surface area is increase of 3x for folds, 10x for hills/valleys, and 200x for microscopic protrusions. Stomach temporary folds rugae they are folding of luminal side of stomach and when receptive relaxation occurs, rugae flatten out this allows for expansion of stomach to increase surface area. Valleys occur as gastric pits: which then lead to gastric glands. Both folding and valley soccur to increase sa. Permanent folds that do not flatten out during expansion (plica) Hills as villi, and valleys as crypts of liberkuhn lots of secretion absorption occurring. Valleys as crypts of lieberkuhn on luminal surface. No villi in large intestine, meaning not as much absorption relative to the small intestine.
