2/3/25, 8:05 AM UPDATED: Physiology NBME (2025)Actual Exam Test|Complete Questions With Verified Answers With Rationales (100% Accur…
UPDATED: Physiology NBME (2025)Actual Exam
Test|Complete Questions With Verified Answers
With Rationales (100% Accurate Solutions)
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Terms in this set (448)
phospholipids make up glycerol backbone - philic head
the lipid bilayer FA tails - phobic - water insoluble
can pass membrane fine O2, CO2, steroid H (fat soluble)
cannot pass membrane Na, Cl, glucose, H20 (hydrophilic things)
alone
nucleolus synthesized rRNA (within the nucleus)
imbedded in/anchored to cell membrane
-hydrophobic interactions
integral proteins
-can span membrane
-G proteins, transport proteins
not imbedded in membrane
peripheral proteins
-attached via electrostatic interactions
zonula occludens
-b/w cells
tight junctions
-for solutes - size, charge
-tight or leaky
attachments b/w cells that permit intercellular
gap junctions communication
-for current flow
not carrier mediated
simple diffusion
-downhill. is passive.
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J(flow) = PA(C1-C2)
P: permeability
A: area
diffusion equation
C: concentration (1 is higher C)
direction will be high to low
in cm
high oil:water ratio
increase permeability low radius of solute
low membrane thickness
primary and secondary AT
-stereospecificity
carrier mediated
-saturation: Tm is = Vmax
-competition: for structurally related solutes
downhill but needs energy
-more rapid
facilitated diffusion
-carrier mediated
-glucose!
against gradient
-ATP - active; carrier mediated
primary AT -Na/K ATPase (Na goes out; K in)
-Ca ATPase (SR - SERCA)
-H,K ATPase: H into lumen
ouabain
Na/K ATPase inhibitors
digitalis
H,K ATPase inhibitor omeprazole
2 or more coupled solutes
-Na downhill to provide energy
2nd AT -indirect help from other transporters (Na gradient)
-symport (Na/glu or Na/K/Cl), antiport (Na/Ca or
Na/H)
concentration of osm active particles in solution
osmolarity
-measured via freezing point depression
osmolarity = g*C
osmolarity equation g = number of particles in sln
C = concentration
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water follows the solute! osmoles!
pie = g C RT
osmotic pressure (Van't -g = number of particles
Hoff's Law) -R = 0.082
-T = absolute Temp (K)
osmotic pressure ____ increases, solute concentration increases
when _____
hyper/hypo osmotic has higher or lower osmole amounts
has higher osmotic P
hypertonic
-will receive water from the hypotonic sln
colloid osmotic osmotic pressure made from proteins
pressure/oncotic
pressure
ease that solute permeates a membrane
-1 = impermeable solute (albumin) --causes water
reflection coefficient
mvment/osm effects (effective)
(sigma)
-0 = completely permeable (urea) -- causes no
water mvment/osmotic effects (ineffective osm)
effective osmotic P osmotic P * reflection coefficient
1. selective: size and charge
ion channels are 2. open/closed
3. conductance: high if open (controlled by gates)
-activation gate of Na: depolarization opens it
Voltage gated
-inactivation gate of Na: depolarization closes it
opened/closed by H, 2nd messengers, nt
ligand gated channels
-nicotinic receptor opens when Ach binds
potential difference generated ax a membrane b/c
of a concentration of an ion
diffusion potential
-membrane must be permeable to the ion
-usually doesn't cause changes in [] of ions
size of DP depends on size of the gradient
whether diffusing ion is positively or negatively
sign of the DP
charged
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electrochemical chemical and electrical (equilibrium potential)
equilibrium driving forces are equal
E = -60/z log10 (Cintra/Cextra)
-2.3(RT/zf) = 60/z
-z is charge (including number) of the ion
Nernst equation -
equilibrium potentials
negative sign tells you the charge inside the cell. So
you can intuitively figure it out by the movement of
the ion
potential Na 65 mV
potential Ca 120
potential K and Cl -85
-70 (cell is negative)
---more permeable to the potentials that are closest
resting membrane
to the resting membrane potential (whatever that
potential
may be)
--in AP: at -70 b/c high conductance to K only
depolarization membrane is more positive (inward current)
hyperpolarization membrane is more negative (outward current)
inward current --> depolarization
-opening of Na channels
-Na conductance > K
upstroke of AP -potential driven to -65
INWARD NA CURRENT
-overshoot
brief portion at the peak of the AP when the
overshoot
membrane potential is positive
Tetrodotoxin block Na channels
(TTX)/lidocaine stop APs
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UPDATED: Physiology NBME (2025)Actual Exam
Test|Complete Questions With Verified Answers
With Rationales (100% Accurate Solutions)
Save
Terms in this set (448)
phospholipids make up glycerol backbone - philic head
the lipid bilayer FA tails - phobic - water insoluble
can pass membrane fine O2, CO2, steroid H (fat soluble)
cannot pass membrane Na, Cl, glucose, H20 (hydrophilic things)
alone
nucleolus synthesized rRNA (within the nucleus)
imbedded in/anchored to cell membrane
-hydrophobic interactions
integral proteins
-can span membrane
-G proteins, transport proteins
not imbedded in membrane
peripheral proteins
-attached via electrostatic interactions
zonula occludens
-b/w cells
tight junctions
-for solutes - size, charge
-tight or leaky
attachments b/w cells that permit intercellular
gap junctions communication
-for current flow
not carrier mediated
simple diffusion
-downhill. is passive.
https://quizlet.com/1000618197/updated-physiology-nbme-2025actual-exam-testcomplete-questions-with-verified-answers-with-rationales-100-a… 1/44
,2/3/25, 8:05 AM UPDATED: Physiology NBME (2025)Actual Exam Test|Complete Questions With Verified Answers With Rationales (100% Accur…
J(flow) = PA(C1-C2)
P: permeability
A: area
diffusion equation
C: concentration (1 is higher C)
direction will be high to low
in cm
high oil:water ratio
increase permeability low radius of solute
low membrane thickness
primary and secondary AT
-stereospecificity
carrier mediated
-saturation: Tm is = Vmax
-competition: for structurally related solutes
downhill but needs energy
-more rapid
facilitated diffusion
-carrier mediated
-glucose!
against gradient
-ATP - active; carrier mediated
primary AT -Na/K ATPase (Na goes out; K in)
-Ca ATPase (SR - SERCA)
-H,K ATPase: H into lumen
ouabain
Na/K ATPase inhibitors
digitalis
H,K ATPase inhibitor omeprazole
2 or more coupled solutes
-Na downhill to provide energy
2nd AT -indirect help from other transporters (Na gradient)
-symport (Na/glu or Na/K/Cl), antiport (Na/Ca or
Na/H)
concentration of osm active particles in solution
osmolarity
-measured via freezing point depression
osmolarity = g*C
osmolarity equation g = number of particles in sln
C = concentration
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,2/3/25, 8:05 AM UPDATED: Physiology NBME (2025)Actual Exam Test|Complete Questions With Verified Answers With Rationales (100% Accur…
water follows the solute! osmoles!
pie = g C RT
osmotic pressure (Van't -g = number of particles
Hoff's Law) -R = 0.082
-T = absolute Temp (K)
osmotic pressure ____ increases, solute concentration increases
when _____
hyper/hypo osmotic has higher or lower osmole amounts
has higher osmotic P
hypertonic
-will receive water from the hypotonic sln
colloid osmotic osmotic pressure made from proteins
pressure/oncotic
pressure
ease that solute permeates a membrane
-1 = impermeable solute (albumin) --causes water
reflection coefficient
mvment/osm effects (effective)
(sigma)
-0 = completely permeable (urea) -- causes no
water mvment/osmotic effects (ineffective osm)
effective osmotic P osmotic P * reflection coefficient
1. selective: size and charge
ion channels are 2. open/closed
3. conductance: high if open (controlled by gates)
-activation gate of Na: depolarization opens it
Voltage gated
-inactivation gate of Na: depolarization closes it
opened/closed by H, 2nd messengers, nt
ligand gated channels
-nicotinic receptor opens when Ach binds
potential difference generated ax a membrane b/c
of a concentration of an ion
diffusion potential
-membrane must be permeable to the ion
-usually doesn't cause changes in [] of ions
size of DP depends on size of the gradient
whether diffusing ion is positively or negatively
sign of the DP
charged
https://quizlet.com/1000618197/updated-physiology-nbme-2025actual-exam-testcomplete-questions-with-verified-answers-with-rationales-100-a… 3/44
, 2/3/25, 8:05 AM UPDATED: Physiology NBME (2025)Actual Exam Test|Complete Questions With Verified Answers With Rationales (100% Accur…
electrochemical chemical and electrical (equilibrium potential)
equilibrium driving forces are equal
E = -60/z log10 (Cintra/Cextra)
-2.3(RT/zf) = 60/z
-z is charge (including number) of the ion
Nernst equation -
equilibrium potentials
negative sign tells you the charge inside the cell. So
you can intuitively figure it out by the movement of
the ion
potential Na 65 mV
potential Ca 120
potential K and Cl -85
-70 (cell is negative)
---more permeable to the potentials that are closest
resting membrane
to the resting membrane potential (whatever that
potential
may be)
--in AP: at -70 b/c high conductance to K only
depolarization membrane is more positive (inward current)
hyperpolarization membrane is more negative (outward current)
inward current --> depolarization
-opening of Na channels
-Na conductance > K
upstroke of AP -potential driven to -65
INWARD NA CURRENT
-overshoot
brief portion at the peak of the AP when the
overshoot
membrane potential is positive
Tetrodotoxin block Na channels
(TTX)/lidocaine stop APs
https://quizlet.com/1000618197/updated-physiology-nbme-2025actual-exam-testcomplete-questions-with-verified-answers-with-rationales-100-a… 4/44
