HTHSCI 1H06 Lecture 19: Tubular Function
Document Summary
Some special chemicals are secreted from blood to tubules (penicillin) What to do with 180 l of filtrate. Some completely reabsorbed: won"t see those in urine. Some excreted as waste: pushed into filtrate or not going to be reabsorbed. Final thing is going to happen in the collecting duct which is variably permeable to water. In the renal cortex we find the distal and proximal tubule and renal corpuscle. Passive transport: no additional energy added, paracellular route and transcellular route. Fluid in tubule lumen: apical membrane brush border that increases the surface area of those cells, tubule cell behind it that has a basolateral membrane that goes into interstitial fluid, tight junctions, a bit leaky. Interstitial fluid, running through it we have peritubular capillary. Sodium always likes to come inside cell because inside is poor in tubule: can move paracellularly when sodium is low inside than tubule lumen, carried away by peritubular capillary.