BIO 126 Lecture 3: Excretory System (32)
6 Apr 2016
School
Department
Course
Professor
Document Summary
Regulation of extracellular luid volume & blood pressure. Fixes water & salt balance after diferent systems cause changes. Osmocon formers- organisms that are in osmotic equilibrium w/ their environment. Osmoregulators- set internal salt & water & keep it there. Removal of salts & water through excretory system. All vertebrates can produce a urine that is isotonic or hypotonic to blood. Only birds and mammals can make a hypertonic urine. Body luids hypertonic w/ respect to surrounding water. Salt can leave body through gills; water can enter. Expend energy to transport excess salt out of body through gill epithelial cells. Filtration: luid in blood is iltered out of glomerulus into tubule system. *blood & plasma membrane does not it through* Reabsorption: selective movement of solutes our of iltrate back into blood via peritubular capillaries. *reabsorption of glucose & amino acids driven by active transport & secondary active transport*
