BIOL3030 Lecture Notes - Lecture 26: Osmotic Pressure, Tonicity, Osmoregulation
4 Apr 2017
School
Department
Course
Professor
Document Summary
Salt: anything that will draw water across a membrane to itself. Osmolarity of environment versus body fluid osmolarity. Limited osmoregulator: over same range of difference, differene can be maintained. Controlling osmolality of their body to be different than outside. Most isosmotic (not necessarily osmoconformers) or hyposmotic. Water environements: largely impermeable to water and slats. Change to ammonium ion nh4 (aquatic) urea (amphibians mammals), uric area (birds reptiles): poop and pee white. Protein shoots through and unfurls to clog gills. Keep other salts out with rectal gland. Punping na out of cell with atpase creates electrochemical gradient favoring na diffusion into cell. This gradient power cotransport of na and cl into cells. Cl diffuses into lumen along its concentration and charge gradients. Na diffuses into lumen along its concentration and charge gradient. Keep salts it wants, getting rid of salts it doesnt. Active extrusion of cl active or passive outflux of na. Small urine amounts: isosmotic rich in mg and so4.
