HIST10014 Lecture Notes - Lecture 17: Water Potential, Water Intoxication, Osmotic Concentration

• School: University of Melbourne
• Department: History
• Course: HIST10014
• Professor: Julie Fedor

Document Summary

Osmosis: water di uses through a semi permeable membrane from an area of low osmotic concentration (low osmolarity, high water potential) to an area of high osmotic concentration (high osmolarity, law water potential) Tonicity: similar to osmolarity except it takes into account only non-permeable solutes. Osmoconformer: osmotic concentration of internal environment is equal to external environment. Osmoregulator: osmotic concentration of internal environment does not equal external environment. Too little thirsty (1% loss) loss of appetite (2%) can"t function physically well (3%) nausea, loss of focus (4%) muscle spasms, delirium (10%) death (20%) Water and solutes are exchanged continuously between an animal and its environment. Terrestrial animals gain or lose water vis osmosis gain or lose solutes by passive di usion across body surface lose water by evaporation from body surface sweating breathing. We must regulate body water and solutes to achieve homeostasis (constancy of the extracellular environment) Ions makes up over 70% of most organism"s body weight.