Physiology 206 1STedition Lecture 27Outline of Last Lecture I. LiverII. GallbladderIII. PeristalsisOutline of Current Lecture I. Sodium ReabsorptionCurrent LectureSodium Reabsorption-Control of body sodium level is controlled by kidney by varying the amount we loseoAll of the control is done in the distal tubeoThe amount that gets reabsorbed in the distal tube determines the amount of sodium in the body-Sodium goes from the lumen of the nephron to the bloodstreamoGets pumped out of the nephron cells into the ECF (active transport)-Allows for sodium in the lumen of the nephron to then move into the celloThen diffuses into the capillaries from ECF-Amount of Sodium Reabsorbedo80% reabsorbed in Proximalo12% in the Loop of Henleo7.5% in the distal tube-Tubular LoadoFor glucose = 1 mg/mL x 125 mL/min = 125 mg/min-Amount of glucose that enters your nephron per minute-Tm of glucoseo400 mg/minoNephrons can absorb up to that amount (if it is present)oMeans that glucose does not wind up in the urine-Water follows concentration of glucose osmoticallyoCauses an overall increase in blood plasmaoDiabetics cannot control glucose levels-Have high urine levels-Have sweet peeThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.-Chloride is reabsorbed passively due to being attracted by the positive charge of sodium-Reabsorbing 99.5% of water (in nephron)oMeans that everything left behind is in higher concentration than beforeoAnything left behind that can diffuse across nephron membrane WILL diffuse-UreaoMain metabolic end product for nitrogen-containing compoundsoCan diffuse very freely across most cell membranesoSecond most rapidly diffusing compound (water is first)oUrea concentration in urine is 50 times as high as anywhere else in the only solely through passive transportoCompletely non-toxic-Most other organisms make ammonia, which is toxic-Ammonia then diffuses out into the water-Terrestrial animals had to evolve to find a non-toxic waste product-Detoxify organic compounds by transforming them into their organic anions-1-2 L of urine per dayoGfiltrate = 180 L per dayoReabsorbed = 179 L per dayoUrine = 1 L per day-Plasma Clearance-InulinoPolysaccharideoLot in artichokes, also in onions and garlic-Can vary amounts in blood plasmaoFreely filtered-Amount in filtrate is the amount in plasma-Not secreted by the body-Not reabsorped by the body-Means that the amount of inulin that entered the urine is the same as the volume of plasma that got filteredoInulin clearance is the GFR (r =
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