2/19/25, 2:08 PM Actual exam for NBME Physiology 2025 update|comprehensive questions and verified answers (complete solutions) GRADE A…
Actual exam for NBME Physiology 2025
update|comprehensive questions and verified
answers (complete solutions) GRADE A+!!
Save
Terms in this set (305)
attachment between cells that permit intercellular
Gap Junctions communication (i.e. current flow and electrical
coupling between myocytes)
J= -PA (C1-C2) The urea conc. of blood is 10 mg/ 100mL the urea
conc of proximal tubular fluid is 20 mg/ 100 mL. if
J= (1x10^-5)(100)[(20/100)- the permeability to urea is 1x10^-5 cm/sec and the
(10/100)] surface area is 100 cm^2 what is the magnitude and
direction of the urea flux (diffusion)?
J= 1x10-4 mg/sec
2 K+ for 3 Na+ Na/K ATPase exchanges ___ K for ___ Na.
Digitalis Specific inhibitor of the Na/K ATPase?
(cardiac glycoside drug)
Ca++ ATPase in the sarcoplasmic and endoplasmic
SERCA
reticulum?
The H/K ATPase that pumps protons into the gastric
Omeprazole (proton
lumen (against their conc. gradient) is inhibited by
pump inhibitor)
what drug?
Flow of water across a semipermeable membrane
Osmosis from a solution with low solute conc. to a solution
with high solute conc. ?
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,2/19/25, 2:08 PM Actual exam for NBME Physiology 2025 update|comprehensive questions and verified answers (complete solutions) GRADE A…
Osmotic pressure ___________ when solute conc.
Increases
increases.
1 M CaCl2 because the Which has a higher osmotic pressure: 1 M CaCl2 or 1
conc. of particles is M KCl?
higher.
Isotonic If two solutions have the same osmotic pressure,
they are _________
Hypertonic
If one solution has a higher osmotic pressure than
Hypotonic the other, it is _____________
**Water flows from the If one solution has a lower osmotic pressure than
hypotonic to the the other, it is __________
hypertonic solution.
Reflection coefficient A number between zero and 1 that describes the
ease with which a solute permeates a membrane?
Rf= 1 means the solute is
IMPERMEABLE (100%
reflection)
Rf= 0 means the solute is
COMPLETELY
PERMEABLE
reflection coefficient of serum albumin? (a large
Rf= 1
solute)
Rf=0
Reflection coefficient of urea? (a small solute)
Small Cations A small ion channel lined with negatively charged
groups will be selective for?
*will exclude large
molecules and anions
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Equilibrium potential Refers to the potential difference that would exactly
balance (oppose) the tendency for diffusion down a
*At electrochemical concentration gradient?
equilibrium, the
chemical and electrical
driving forces that act
on an ion are equal and
opposite*, and no more
net diffusion of the ion
occurs.
Approximate equilibrium potentials in nerve and
muscle?
E Na= +65 mV
E Na= ?
E Ca= +120 mV
E Ca= ?
E K= -85 mV
E K= ?
E Cl= -85 mV
E Cl= ?
Depolarization (cell __________ makes the membrane potential less negative
interior becomes less
negative) _________ makes the membrane potential more
negative
Repolarization (cell
interior becomes more
negative
Inward current Refers to the flow of positive charge into the cell?
**depolarizes the cell (current)
outward current Refers to the flow of positive charge out of the cell?
**hyperpolarizes the cell (current)
NO: Action potentials are Are action potentials different sizes dependent on
all or nothing different magnitudes of stimuli?
The membrane potential at which an action
Threshold
potential is inevitable?
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, 2/19/25, 2:08 PM Actual exam for NBME Physiology 2025 update|comprehensive questions and verified answers (complete solutions) GRADE A…
-70 mV Normal resting membrane potential?
**A result of the high
resting conductance to
K+ which drives the
membrane potential
toward the K+ equilibrium
potential (-85 mV)
1. Inward current What causes the upstroke of the action potential?
depolarizes the
membrane potential to
threshold
2. Depolarization causes
opening of Na channels
3. Rapid depolarization
occurs due to the
increased conductance
of Na (inward Na
Current)
**brief period where
membrane potential is
positive
Repolarization is caused What causes repolarization of the action potential?
by an OUTWARD K+
current
Tetrodotoxin (TTX) Two drugs that block voltage gated Na channels,
abolishing action potentials?
Lidocaine
Tetraethylammonium Drug that blocks voltage gated K+ channels?
(TEA)
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Actual exam for NBME Physiology 2025
update|comprehensive questions and verified
answers (complete solutions) GRADE A+!!
Save
Terms in this set (305)
attachment between cells that permit intercellular
Gap Junctions communication (i.e. current flow and electrical
coupling between myocytes)
J= -PA (C1-C2) The urea conc. of blood is 10 mg/ 100mL the urea
conc of proximal tubular fluid is 20 mg/ 100 mL. if
J= (1x10^-5)(100)[(20/100)- the permeability to urea is 1x10^-5 cm/sec and the
(10/100)] surface area is 100 cm^2 what is the magnitude and
direction of the urea flux (diffusion)?
J= 1x10-4 mg/sec
2 K+ for 3 Na+ Na/K ATPase exchanges ___ K for ___ Na.
Digitalis Specific inhibitor of the Na/K ATPase?
(cardiac glycoside drug)
Ca++ ATPase in the sarcoplasmic and endoplasmic
SERCA
reticulum?
The H/K ATPase that pumps protons into the gastric
Omeprazole (proton
lumen (against their conc. gradient) is inhibited by
pump inhibitor)
what drug?
Flow of water across a semipermeable membrane
Osmosis from a solution with low solute conc. to a solution
with high solute conc. ?
https://quizlet.com/1007883960/actual-exam-for-nbme-physiology-2025-updatecomprehensive-questions-and-verified-answers-complete-solutio… 1/56
,2/19/25, 2:08 PM Actual exam for NBME Physiology 2025 update|comprehensive questions and verified answers (complete solutions) GRADE A…
Osmotic pressure ___________ when solute conc.
Increases
increases.
1 M CaCl2 because the Which has a higher osmotic pressure: 1 M CaCl2 or 1
conc. of particles is M KCl?
higher.
Isotonic If two solutions have the same osmotic pressure,
they are _________
Hypertonic
If one solution has a higher osmotic pressure than
Hypotonic the other, it is _____________
**Water flows from the If one solution has a lower osmotic pressure than
hypotonic to the the other, it is __________
hypertonic solution.
Reflection coefficient A number between zero and 1 that describes the
ease with which a solute permeates a membrane?
Rf= 1 means the solute is
IMPERMEABLE (100%
reflection)
Rf= 0 means the solute is
COMPLETELY
PERMEABLE
reflection coefficient of serum albumin? (a large
Rf= 1
solute)
Rf=0
Reflection coefficient of urea? (a small solute)
Small Cations A small ion channel lined with negatively charged
groups will be selective for?
*will exclude large
molecules and anions
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,2/19/25, 2:08 PM Actual exam for NBME Physiology 2025 update|comprehensive questions and verified answers (complete solutions) GRADE A…
Equilibrium potential Refers to the potential difference that would exactly
balance (oppose) the tendency for diffusion down a
*At electrochemical concentration gradient?
equilibrium, the
chemical and electrical
driving forces that act
on an ion are equal and
opposite*, and no more
net diffusion of the ion
occurs.
Approximate equilibrium potentials in nerve and
muscle?
E Na= +65 mV
E Na= ?
E Ca= +120 mV
E Ca= ?
E K= -85 mV
E K= ?
E Cl= -85 mV
E Cl= ?
Depolarization (cell __________ makes the membrane potential less negative
interior becomes less
negative) _________ makes the membrane potential more
negative
Repolarization (cell
interior becomes more
negative
Inward current Refers to the flow of positive charge into the cell?
**depolarizes the cell (current)
outward current Refers to the flow of positive charge out of the cell?
**hyperpolarizes the cell (current)
NO: Action potentials are Are action potentials different sizes dependent on
all or nothing different magnitudes of stimuli?
The membrane potential at which an action
Threshold
potential is inevitable?
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, 2/19/25, 2:08 PM Actual exam for NBME Physiology 2025 update|comprehensive questions and verified answers (complete solutions) GRADE A…
-70 mV Normal resting membrane potential?
**A result of the high
resting conductance to
K+ which drives the
membrane potential
toward the K+ equilibrium
potential (-85 mV)
1. Inward current What causes the upstroke of the action potential?
depolarizes the
membrane potential to
threshold
2. Depolarization causes
opening of Na channels
3. Rapid depolarization
occurs due to the
increased conductance
of Na (inward Na
Current)
**brief period where
membrane potential is
positive
Repolarization is caused What causes repolarization of the action potential?
by an OUTWARD K+
current
Tetrodotoxin (TTX) Two drugs that block voltage gated Na channels,
abolishing action potentials?
Lidocaine
Tetraethylammonium Drug that blocks voltage gated K+ channels?
(TEA)
https://quizlet.com/1007883960/actual-exam-for-nbme-physiology-2025-updatecomprehensive-questions-and-verified-answers-complete-solutio… 4/56
