PHSI2006 Study Guide - Final Guide: Oncotic Pressure, Extracellular Fluid, Fluid Compartments

• School: University of Sydney
• Department: Physiology
• Course: PHSI2006
• Professor: phsi2006

Document Summary

These two fluids are seperated by capillary membranes. Intracellular and extracellular fluid: these two are seperated by the cell membranes which are semi- permeably to water. Water will move across by osmosis and will move down its concentration gradient. E. g. when you are dehydrated you will have less ecf and water will move from icf to ecf and the cells will shrink. Homeostasis of the ecf is by the kidneys (our body cannot regulate the icf, u do it by ecf because they are in equilibrium: we can break down the composition of fluids into solute composition and protein composition. Each of these exert a hydrostatic pressure which can drive movement of water by osmosis. 100mmol/l cl: so it has a 200mosmol/l osmolarity, compare this to 100mmol/l glucose the osmolarity of this solution is 100mosmol/kg because it doesn"t dissociate, it is only one molecule. The nacl will have more of an effect on water movement because it has double osmolarity.