BIOL 2420 Lecture Notes - Lecture 15: Tonicity, Collecting Duct System, Distal Convoluted Tubule

• School: University of Manitoba
• Department: Biological Sciences
• Course: BIOL 2420
• Professor: W.G.Anderson

Document Summary

Addition to measurement of renal function - slide 23. Volume of plasma per unit time from which all of a substance is removed. If ration is 1 (in the equation at the bottom of the page) - no extra water will be reabsorbed. But if the ration is 1/2 then 50% of the water will be reabsorbed, the other half will be excreted. The osmolality of body uids is closely regulated near 300 mosm/l. However, urine concentration can range from 80 to >1200 mosm/l. We can concentrate ruin 4 times that of our plasma conc. This ability depends on the presence of a vertical osmotic gradient in the isf of the renal medulla. 2 main factors: selective permeabilities in the nephron. Regulates water uptake and changes the osmolarity of urine. Establishes a gradient and concentrated the urine. A 2nd countercurrent system (vasa recta) prevents dissolution of this gradient.