Body Fluid Compartments Flashcards
Define Isooncotic
Same amount of albumin, for human 1 mM of albumin/L plasma
Define Isosmotic
Same number of ions
Isotonic
Same solute and solution concentration
Define Osmotic pressure
The hydrostatic pressure required to prevent fluid from leaving a compartment
What is the osmolarity of plasma?
292 millimoles solute/Liter
What is the role of Albumin?
Carries fatty acids,Ca+ and acts as a H+ buffer
What is the concentration of Cl- in plasma? Na+, Bicarb?
103, 140, 27
What is the typical range for anion gap?
10-14
Describe milliosmoles
millimoles of total free solute
What is the difference between Osmolarity and Osmolality?
Osmolarity is millimoles/Liter and Osmolality / Kg
Why is the reference osmolatity 292 and not the calculated 300?
Some Ca+ and albumin are bound which reduces osmolatlity.
What is the equation for fluid movement across a semi-permeable membrane?
K(Pc+pi(if))-(Pif+pi(c)) where P = hydrostatic and pi = osmotic.
When you drink water where does it go?
To all 3 compartments in the corresponding volume ratio.
Describe what happens when you give a normal saline infusion?
Distributes to the plasma and interstitial fluid in the corresponding ratio of body water. Does not enter cells becuase of Na/K pumps
Describe what happens when you give 1/2 normal saline?
half distributes as water and the other half (the saline part) distributes to the Plasma and ISF.
Describe what happens when you give isoncotic saline? Also called artifical plasma
It distributes just in the plasma but does leave to ISF via hydrostatic pressure and return via oncotici pressure.
Describe what happens when you give a person 5% dextrose?
It distributes into all 3 compartment as Glucose gets oxidized or is converted to glycogen or fat. The fluid distributes in ratio equal to TBW.
