GMS 6401 ACTUAL EXAM QUESTIONS
AND COMPLETE STUDY GUIDE 2026
▶ what is the dilution principle. Answer: an exact quantity of a soluble
substance is dissolved in an unknown volume of water, after equilibration,
when the soluble substance is evenly diluted throughout the water, the
concentration can be ,measured
volume can be found by dividing the exact quantity of the soluble
substance added by the concentration at equilibrium (look at slide for
formulas)
▶ what are the criteria for measurement of volume of a particular fluid
compartment. Answer: substance must be freely distributed through entire
compartment
must be non toxic
not metabolized
easily measured
▶ example of measuring an unknown volume. Answer: add 100 g of blue
dye
mix until concentration equilibrates
concentration at equilibrium is 20 g/liter
what is volume?
(100g)/(20 g/L) --> 5 liters
▶ how do we measure plasma volume. Answer: use 131 iodine-labelled
albumin or EVANS BLUE dye
this binds to plasma proteins and stays in plasma
▶ how do we measure the extracellular fluid volume (plasma and interstitial
fluid). Answer: cannot enter cell, must stay in plasma & interstitial fluid
use inulin (sugar that is foreign to body)
also can use radio labeled sodium or chloride
, *need to use substance that can move freely across capillary wall but not
enter cell
▶ how do we measure the volume of the total body water. Answer:
substance used must cross cell membrane freely
use titrated water and 'heavy water, D20' (not radioactive)
take sample from plasma membrane
LOOK AT REVIEW SLIDE
▶ how do we measure the volume of the intracellular fluid. Answer: cannot
be measured directly
calculate total body water and subtract extracellular fluid volume
▶ what is the capillary wall. Answer: barrier separating the plasma and
interstitial compartments
passive transport and exchange
passive exchange driven by chemical concentration gradient
semi-permeable
▶ why are capillaries so important. Answer: where nutrients, O2, and CO2
are exchanged
have larger surface area to increase exchange
▶ what is hydrostatic pressure (Pc). Answer: fluid pressure of blood
pushes water and solutes out of the capillaries
forward motion of blood requires falling hydrostatic pressure through
vessels from arterial end to venous end
higher on arterial end
lower on venous end
▶ what is the colloid osmotic pressure (pic). Answer: opposite hydrostatic
pressure
due to plasma proteins that can't cross the wall
try to pull fluids and solutes back in (absorption)
higher on venous end of capillary
lower on arterial end of capillary
increases when fluid leaves capillary
▶ what is oncotic pressure. Answer: hydrostatic pressure - colloid osmotic
pressure
AND COMPLETE STUDY GUIDE 2026
▶ what is the dilution principle. Answer: an exact quantity of a soluble
substance is dissolved in an unknown volume of water, after equilibration,
when the soluble substance is evenly diluted throughout the water, the
concentration can be ,measured
volume can be found by dividing the exact quantity of the soluble
substance added by the concentration at equilibrium (look at slide for
formulas)
▶ what are the criteria for measurement of volume of a particular fluid
compartment. Answer: substance must be freely distributed through entire
compartment
must be non toxic
not metabolized
easily measured
▶ example of measuring an unknown volume. Answer: add 100 g of blue
dye
mix until concentration equilibrates
concentration at equilibrium is 20 g/liter
what is volume?
(100g)/(20 g/L) --> 5 liters
▶ how do we measure plasma volume. Answer: use 131 iodine-labelled
albumin or EVANS BLUE dye
this binds to plasma proteins and stays in plasma
▶ how do we measure the extracellular fluid volume (plasma and interstitial
fluid). Answer: cannot enter cell, must stay in plasma & interstitial fluid
use inulin (sugar that is foreign to body)
also can use radio labeled sodium or chloride
, *need to use substance that can move freely across capillary wall but not
enter cell
▶ how do we measure the volume of the total body water. Answer:
substance used must cross cell membrane freely
use titrated water and 'heavy water, D20' (not radioactive)
take sample from plasma membrane
LOOK AT REVIEW SLIDE
▶ how do we measure the volume of the intracellular fluid. Answer: cannot
be measured directly
calculate total body water and subtract extracellular fluid volume
▶ what is the capillary wall. Answer: barrier separating the plasma and
interstitial compartments
passive transport and exchange
passive exchange driven by chemical concentration gradient
semi-permeable
▶ why are capillaries so important. Answer: where nutrients, O2, and CO2
are exchanged
have larger surface area to increase exchange
▶ what is hydrostatic pressure (Pc). Answer: fluid pressure of blood
pushes water and solutes out of the capillaries
forward motion of blood requires falling hydrostatic pressure through
vessels from arterial end to venous end
higher on arterial end
lower on venous end
▶ what is the colloid osmotic pressure (pic). Answer: opposite hydrostatic
pressure
due to plasma proteins that can't cross the wall
try to pull fluids and solutes back in (absorption)
higher on venous end of capillary
lower on arterial end of capillary
increases when fluid leaves capillary
▶ what is oncotic pressure. Answer: hydrostatic pressure - colloid osmotic
pressure
