BIO310H5 Lecture : Lecture #17.docx
Document Summary
Peritubular capillary very close the nephron for reabsorption. Tubular lumen has brush borders that increase surface area that improve reabsorption. most of it occurs via active transport. 67% of na is reabsorbed at the pct (even though not very permeable to sodium it has pumps to help) Glucose goes through facilitated diffusion because its really big (but it still has concentration gradient) the local increase of na+ in if helps increase the movment of water to the if. At the distal and collecting duct hormones regulate permability. Collecting duct will have many nephrons draining into it. if there is excess salts then there will be last second reabsorption at the collecting duct regulated by hormones. Coutnercurrent mulitplier system arises from countercurrent very easily seen in longer nephrons. Note that it goes the opposite way of the loop of henle filtration is always happening.
