Physiology 206 1STedition Lecture 27 Outline of Last Lecture I Liver II Gallbladder III Peristalsis Outline of Current Lecture I Sodium Reabsorption Current Lecture Sodium Reabsorption Control of body sodium level is controlled by kidney by varying the amount we lose o All of the control is done in the distal tube o The 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 bloodstream o Gets 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 cell o Then diffuses into the capillaries from ECF Amount of Sodium Reabsorbed o 80 reabsorbed in Proximal o 12 in the Loop of Henle o 7 5 in the distal tube Tubular Load o For glucose 1 mg mL x 125 mL min 125 mg min Amount of glucose that enters your nephron per minute Tm of glucose o 400 mg min o Nephrons can absorb up to that amount if it is present o Means that glucose does not wind up in the urine Water follows concentration of glucose osmotically o Causes an overall increase in blood plasma o Diabetics cannot control glucose levels Have high urine levels Have sweet pee These 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 o Means that everything left behind is in higher concentration than before o Anything left behind that can diffuse across nephron membrane WILL diffuse Urea o Main metabolic end product for nitrogen containing compounds o Can diffuse very freely across most cell membranes o Second most rapidly diffusing compound water is first o Urea concentration in urine is 50 times as high as anywhere else in the only solely through passive transport o Completely 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 day o Gfiltrate 180 L per day o Reabsorbed 179 L per day o Urine 1 L per day Plasma Clearance Inulin o Polysaccharide o Lot in artichokes also in onions and garlic Can vary amounts in blood plasma o Freely 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 filtered o Inulin clearance is the GFR r rate
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