Fluid Compartments Flashcards
What percentage of the fluid in the body is intracellular?
55%
What percentage of the fluid in the body is extracellular?
interstitial?
plasma?
transcellular?
45%
36%
7 %
2%
What are the main cations and anions found inside and outside cells?
Na+, K+, Ca2+
Cl-, Organic Phosphates, Proteins
What is the concentration, in mmol/l, of Na+, K+ and Ca2+ found inside and outside the cells?
Na+ - inside: low outside: high
K+ - inside: high , outside: low
Ca2+ - inside: low outside: high
What is the concentration, in mmol/l, of Cl-, Organic Phosphates and proteins found inside and outside the cells?
Protein – outside low inside high
Cl- - outside: high, inside: low
Organic Phosphates – outside: low , inside: high
What is the pH inside and outside cells?
- 4 outside
- 1 inside
therefore higher outside
more acidic inside
Define osmolarity
the measure of the concentration of all solute particles in a solution
In which direction does water move due to osmosis?
Towards the area of higher osmolarity
What feature does osmolarity not take into account?
Membrane permeability to ions
Define tonicity
The strength of a solution as it affects final cell volume
this is based on both permeability and solution composition
What do hypertonic, hypotonic and isotonic solutions do?
Hypertonic – make cells shrink (osmolarity is small inside)
Hypotonic – make cells swell (osmolarity is big inside)
Isotonic – cells don’t change
What feature do real cells have which prevents them from bursting due to having a higher osmolarity inside the cell than outside?
They have sodium-potassium pumps – maintains a lower concentration of sodium inside than outside
What two forces affect the movement of fluid between the capillary and the interstitial space?
Colloid Osmotic Pressure
Hydrostatic Pressure
if COP< hydrostatic then fluid leaks out
if COP> hydrostatic then fluid pulled in
What is oedema?
Abnormal collection of fluid in the interstitium due to the leakage of fluid from capillaries (leakage exceeds capacity of the lymphatics to collect and return it to the circulation)
what is transcytosis?
movement of large molecules
