Renal Physiology I RPF: renal plasma flow ATI: contraction, endo relaxes of mesangial cells. We generally make less protein due to liver disease to alter osmotic pressure in GC. Proteinuria: proteins filtered into urine When kidney transplant occurs the recipient will have the same blood pressure as the donor. Basement membrane (podocytes). and pore size contributes to the barrier emptying into bowmans space. 3 things: endothelial cells, basement membrane and podocytes form the barrier than needs to be crossed. Positive charges get filtered better than neutral or negative charges. The barrier must have a net negative charge associated with it via the basement membrane. Inulin is used to measure GFR. Ultrafiltrate has the same composition as plasma minus the proteins. Only proteins will exert osmotic pressure. GC are different from systemic because they are always filtering. Because we lose volume in the PCT, inulin concentration actually increases, nothing is being secreted. Myogenic mechanism Tubuloglomerular feedback. ECFV: extracellular fluid volume First half of PCT, mostly na and bicarbonate reabsorption. Second half is going to be na and cl-, we are also now using more paracellular transport instead of transcellular K and Ca are transported through paracellular transport between the tight junctions via solvent drag. Fluid flow occurs because slight difference in salitness from outside to inside. As chloride is moved paracellular (and has neg charge) it leaves behind a positive potential. This will leave a positive potential that will push sodium and Ca and K across First half of PCT is low affinity high transport, second part is high affinity low transport velocity.