GMS 6401 CERTIFICATION EXAM
QUESTIONS AND VERIFIED
ANSWERS 2026
▶ secondary active transport. Answer: requires 2 transporters
indirectly powered by ATP
movement of 1 molecule based on movement of another molecule
use Na/K ATPase as primary transporter
Na/glucose is second transporter
1 sodium moves back into cell with 1 glucose molecule
▶ pump-leak model. Answer: simultaneous and independent events
Na/K ATPase pump (low to high)
K leak channel (high to low)
▶ electrical chemical gradient. Answer: when K+ leaks out of cell, leaves
behind - charged anion
cell inside is more negative
creates electrical gradient to pull K+ back inside cell
▶ what controls the electrochemical equilibrium potential in the cell?.
Answer: concentration gradient of the single ion
permeability of membrane
▶ what ion contributes the most to the resting membrane potential.
Answer: K+
gets resting membrane potential to about -90 mV
▶ what is the cell's resting membrane potential. Answer: -90 mV
▶ metabolic acidosis. Answer: can result in hyperkalemia
pH drop
H+ ions pumping into cell
K+ leaves cell, more in extracellular fluid
consequences:
,disturbs heart (arrhythmias)
treatment:
enhance Na/K ATPase to take in more K+ in cell, insulin injection
▶ rhabdomyolysis. Answer: muscle crush leads to cardiac cell electrical
imbalance
crush releases K+ into plasma
hyperkalemia
excess K+ goes thru leaky channel into cardiac cells
cardiac cell potential less negative (depolarized)
leads to cardiac arrhythmias
▶ what percent of the total body weight is water. Answer: 60%
▶ what % of the body weight is extracellular fluid. Answer: 20%
▶ what % if the body weight is intracellular fluid. Answer: 40%
▶ what percent of the body weight is interstitial fluid. Answer: 3/4 of ECF
▶ what % of the body weight is plasma. Answer: 4-5%
1/4 of ECF
▶ what are the components of the blood. Answer: hematocrit is 45%
plasma is 55%
▶ what % of the body weight is blood volume. Answer: 8%
▶ what are the main body fluid compartments. Answer: intracellular
extracellular
▶ what are the components of the extracellular fluid. Answer: interstitial
(between cells)
plasma (in blood)
▶ what is the plasma membrane. Answer: between intra and extracellular
compartments
complex lipid bilayer
has transporters, carriers, pores
, ▶ what molecule is able to move freely between all compartments
(intracellular, interstitial, and plasma). Answer: water
▶ 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)
QUESTIONS AND VERIFIED
ANSWERS 2026
▶ secondary active transport. Answer: requires 2 transporters
indirectly powered by ATP
movement of 1 molecule based on movement of another molecule
use Na/K ATPase as primary transporter
Na/glucose is second transporter
1 sodium moves back into cell with 1 glucose molecule
▶ pump-leak model. Answer: simultaneous and independent events
Na/K ATPase pump (low to high)
K leak channel (high to low)
▶ electrical chemical gradient. Answer: when K+ leaks out of cell, leaves
behind - charged anion
cell inside is more negative
creates electrical gradient to pull K+ back inside cell
▶ what controls the electrochemical equilibrium potential in the cell?.
Answer: concentration gradient of the single ion
permeability of membrane
▶ what ion contributes the most to the resting membrane potential.
Answer: K+
gets resting membrane potential to about -90 mV
▶ what is the cell's resting membrane potential. Answer: -90 mV
▶ metabolic acidosis. Answer: can result in hyperkalemia
pH drop
H+ ions pumping into cell
K+ leaves cell, more in extracellular fluid
consequences:
,disturbs heart (arrhythmias)
treatment:
enhance Na/K ATPase to take in more K+ in cell, insulin injection
▶ rhabdomyolysis. Answer: muscle crush leads to cardiac cell electrical
imbalance
crush releases K+ into plasma
hyperkalemia
excess K+ goes thru leaky channel into cardiac cells
cardiac cell potential less negative (depolarized)
leads to cardiac arrhythmias
▶ what percent of the total body weight is water. Answer: 60%
▶ what % of the body weight is extracellular fluid. Answer: 20%
▶ what % if the body weight is intracellular fluid. Answer: 40%
▶ what percent of the body weight is interstitial fluid. Answer: 3/4 of ECF
▶ what % of the body weight is plasma. Answer: 4-5%
1/4 of ECF
▶ what are the components of the blood. Answer: hematocrit is 45%
plasma is 55%
▶ what % of the body weight is blood volume. Answer: 8%
▶ what are the main body fluid compartments. Answer: intracellular
extracellular
▶ what are the components of the extracellular fluid. Answer: interstitial
(between cells)
plasma (in blood)
▶ what is the plasma membrane. Answer: between intra and extracellular
compartments
complex lipid bilayer
has transporters, carriers, pores
, ▶ what molecule is able to move freely between all compartments
(intracellular, interstitial, and plasma). Answer: water
▶ 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)
