BIOL 221 Lecture Notes - Lecture 6: Renal Physiology, Extracellular Fluid, Reabsorption
Document Summary
Filtered load: amount of solute filtered per unit time, if solute is freely filtered , load = gfr x plasma concentration, e. g. , for na+ (plasma conc. Filtered load refers to the amount of solute that is filtered per unit time. If the solute is freely filtered then load is equal to the amount filtered per unit time (gfr) times the concentration of the solute in the plasma. For example, the plasma concentration of sodium is around 0. 14 milliequivalents per milliliter (meq/ml). If the gfr is 125 milliliters per minute (ml/min), then the filtered load is 17. 5 meq/min. Tubular processing includes tubular reabsorption, which brings solutes and water back into the interstitial fluid (then into the blood), and tubular secretion, which removes solutes from the interstitial fluid (coming from the blood). Sites of reabsorption: proximal convoluted tubule (pct, 65% to 99% of desirable solutes, ~65% of the filtered water, nephron loop water, na+, cl-, k+