PSL301H1 Lecture Notes - Lecture 3: Oliguria, Plasma Osmolality, Angiotensin-Converting Enzyme

• School: UTSG
• Department: Physiology
• Course: PSL301H1
• Professor: all

Document Summary

Intracellular fluid (icf) volume within cells: 28l. Extracellular fluid (ecf) volume of fluid outside the cell: 14l. Plasma (aqueous: a portion of blood): 3. 5 l. Interstitial fluid (isf) bathing the cell: 10. 5l. There is a set point where your body is trying to get the fluid around a certain point. So, if everything is working normally input should be bigger than output. Since you can"t measure the concentration of ions inside, so we measure the concentration on the outside so we try and infer the concentration on the inside. Concentration is the amount of solute in given volume of solvent. Osmolality is the amount of solute particles in a given weight of solvent. Plasma osmolality is 280 300 mosm/kg. (convenient way): estimated as 2[na+] (predominant molecule) + [glucose] + [urea] Osmolarity is the amount of solute particles in 1 kg of water. Applies to dilute aqueous solutions; e. g. urine (can use osmolarity and osmolality interchangeable)