PSL301H1 Lecture Notes - Lecture 31: Peptic Ulcer, Cholecystokinin, Bilirubin
41
PSL301H1 Full Course Notes
Verified Note
41 documents
Document Summary
Specialization of specific regions in the gi tract. Recall that we have function of gi tract, motility patterns, and the concept of material moving through depending on where it is in the gi tract with different motility patterns, but it becomes more specialized as you go through. Pushing through in esophagus, grinding in stomach, and segmentation in the intestine which helps to mix material that is being secreted in the duodenum: material being secreted is the focus of today. Secretion is material into the gi tract to help with digestion and protection, but secretion of hormones or paracrine factors which influence cells to respond. All the material being reabsorbed after secretion requires huge surface area, other(cid:449)ise (cid:449)e"d (cid:271)e deh(cid:455)drated. Absorption is a function of the surface area over which the material interacts. Folds in the tube, and hills/valleys in the folds, and microscopic protrusions mostly on the hills all magnify the surface area over which the material can be reabsorbed.
