GMS 6440
OBJECTIVE ASSESSMENT - EXAM
GMS 6440 Fundamentals Of Medical
Physiology Final Exam Questions With
Correct Answers, 100% Guaranteed Pass
|| Complete A+ Guide
Certification Exam | Medical Physiology
100 100% 2026/2027
QUESTIONS VERIFIED ANSWERS EDITION
TOPICS COVERED
o Membrane Transport and Action Potentials
o Synaptic Transmission and Sensory Processing
o Cardiac Electrophysiology and Hemodynamics
o Renal Tubular Function and Acid-Base Balance
o Hormone Receptors and Signal Transduction
o GI Motility, Secretion, and Nutrient Absorption
COVER PAGE - 1
, SECTION 1 | Cell Physiology and Membrane Transport | Q1-Q20 | GMS 6440 Fundamentals Of Medical Phy
Q1 Question 1 of 100
A 45-year-old patient presents with muscle weakness after starting a new diuretic. Laboratory studies
reveal hypokalemia. The physician explains that the resting membrane potential of skeletal muscle is
determined primarily by the permeability of the cell membrane to potassium ions and the
concentration gradient maintained by the Na+/K+-ATPase pump. Which of the following best
describes the effect of severe hypokalemia on the resting membrane potential of skeletal muscle?
A. The resting membrane potential becomes more negative, making the cell hyperpolarized and less
excitable.
B. The resting membrane potential becomes less negative, causing depolarization and increased
excitability.
C. The resting membrane potential remains unchanged because the Na+/K+-ATPase pump compensates
for potassium shifts.
D. The resting membrane potential becomes zero as potassium equilibrium is reached across the
membrane.
Correct Answer: A
Rationale:
Severe hypokalemia increases the transmembrane potassium gradient, making the intracellular environment more
negative relative to extracellular fluid. This hyperpolarization moves the resting membrane potential further from
threshold, reducing excitability and causing muscle weakness.
Q2 Question 2 of 100
A researcher is studying ion channel kinetics in a cultured neuron. She observes that applying a
depolarizing voltage step opens voltage-gated sodium channels rapidly, but they inactivate within
milliseconds even though depolarization continues. Which structural domain of the voltage-gated
sodium channel is primarily responsible for this fast inactivation?
A. The S4 voltage sensor helices that detect membrane potential changes.
B. The intracellular loop between domains III and IV that acts as a hinged lid.
C. The pore loop (P-loop) containing the selectivity filter residues.
D. The extracellular N-terminal domain that modulates channel trafficking.
Correct Answer: B
Rationale:
Fast inactivation of voltage-gated sodium channels is mediated by the intracellular loop connecting domains III and IV,
which folds into the intracellular mouth of the pore like a hinged lid. The S4 helices detect voltage, the P-loop
determines ion selectivity, and the N-terminus is not involved in inactivation gating.
40 Fundamentals Of Medical Physiology Final Exam Questions With Correct Answers, 100% Guaranteed Pass || Complete A+ Guide - 2026/2027 | Passing Score: 80% | Pag
, SECTION 1 | Cell Physiology and Membrane Transport | Q1-Q20 | GMS 6440 Fundamentals Of Medical Phy
Q3 Question 3 of 100
A 62-year-old man with heart failure is treated with digoxin, which inhibits the Na+/K+-ATPase pump
in cardiac myocytes. The physician explains that this inhibition indirectly increases intracellular
calcium by altering the sodium gradient. Which transport mechanism is primarily responsible for this
secondary increase in cytosolic calcium concentration?
A. The sarcoplasmic reticulum Ca2+-ATPase (SERCA) pump, which sequesters calcium into the SR.
B. The Na+/Ca2+ exchanger (NCX), which normally extrudes calcium using the sodium gradient.
C. The plasma membrane Ca2+-ATPase (PMCA) pump, which directly pumps calcium out of the cell.
D. The voltage-gated L-type calcium channel, which allows calcium influx during depolarization.
Correct Answer: B
Rationale:
The Na+/Ca2+ exchanger normally uses the electrochemical sodium gradient to extrude calcium from the cell.
Digoxin-induced Na+/K+-ATPase inhibition raises intracellular sodium, reducing the sodium gradient and causing NCX
to operate in reverse or slow forward transport, thereby increasing intracellular calcium and contractility.
Q4 Question 4 of 100
A medical student is reviewing the differences between action potentials in skeletal muscle and
cardiac pacemaker cells. She notes that cardiac pacemaker cells in the sinoatrial node lack a stable
resting membrane potential. Which ionic current is primarily responsible for the spontaneous phase 4
depolarization that characterizes pacemaker automaticity?
A. The rapid influx of Na+ through voltage-gated sodium channels (INa).
B. The funny current (If), a mixed Na+/K+ inward current activated by hyperpolarization.
C. The sustained outward K+ current (IKs) that maintains repolarization.
D. The L-type calcium current (ICa-L) that drives the upstroke of the action potential.
Correct Answer: B
Rationale:
The funny current (If) is a hyperpolarization-activated mixed cation current (Na+/K+) carried primarily by HCN
channels. It slowly depolarizes the pacemaker cell during phase 4, bringing the membrane toward threshold. INa is
absent in nodal cells, IKs maintains plateau repolarization, and ICa-L drives the upstroke but does not initiate phase 4.
40 Fundamentals Of Medical Physiology Final Exam Questions With Correct Answers, 100% Guaranteed Pass || Complete A+ Guide - 2026/2027 | Passing Score: 80% | Pag
, SECTION 1 | Cell Physiology and Membrane Transport | Q1-Q20 | GMS 6440 Fundamentals Of Medical Phy
Q5 Question 5 of 100
A 28-year-old athlete collapses during a marathon and is found to have rhabdomyolysis. Laboratory
analysis shows markedly elevated serum creatine kinase and hyperkalemia. The emergency
physician explains that the elevated extracellular potassium can depolarize skeletal muscle
membranes. Which concept best explains why sustained depolarization from hyperkalemia
paradoxically causes muscle weakness rather than sustained contraction?
A. Voltage-gated sodium channels enter inactivated states and cannot recover at depolarized potentials.
B. The Na+/K+-ATPase pump is overwhelmed and stops functioning entirely.
C. Potassium channels open fully and hyperpolarize the membrane beyond resting potential.
D. Calcium channels become blocked, preventing excitation-contraction coupling.
Correct Answer: A
Rationale:
Sustained depolarization from hyperkalemia causes voltage-gated sodium channels to inactivate and enter a
refractory state. Because these channels cannot recover from inactivation at depolarized potentials, no new action
potentials can be generated, resulting in flaccid paralysis despite the depolarized membrane.
Q6 Question 6 of 100
A researcher is examining epithelial transport in the proximal tubule of the kidney. She observes that
glucose is reabsorbed against its concentration gradient from the tubular lumen into the epithelial
cell. Which transport mechanism correctly describes this process, and what ion provides the driving
force?
A. Facilitated diffusion via GLUT transporters, driven by the intracellular glucose concentration.
B. Secondary active transport via SGLT transporters, driven by the sodium electrochemical gradient.
C. Primary active transport via Na+/K+-ATPase, which directly pumps glucose against its gradient.
D. Osmosis through aquaporin channels, driven by the tubular osmotic gradient.
Correct Answer: B
Rationale:
Proximal tubular glucose reabsorption occurs via SGLT (sodium-glucose linked transporters), which are secondary
active symporters. They use the sodium electrochemical gradient established by basolateral Na+/K+-ATPase to
cotransport glucose uphill into the cell. GLUT transporters mediate passive facilitated diffusion, and Na+/K+-ATPase
does not transport glucose directly.
40 Fundamentals Of Medical Physiology Final Exam Questions With Correct Answers, 100% Guaranteed Pass || Complete A+ Guide - 2026/2027 | Passing Score: 80% | Pag
OBJECTIVE ASSESSMENT - EXAM
GMS 6440 Fundamentals Of Medical
Physiology Final Exam Questions With
Correct Answers, 100% Guaranteed Pass
|| Complete A+ Guide
Certification Exam | Medical Physiology
100 100% 2026/2027
QUESTIONS VERIFIED ANSWERS EDITION
TOPICS COVERED
o Membrane Transport and Action Potentials
o Synaptic Transmission and Sensory Processing
o Cardiac Electrophysiology and Hemodynamics
o Renal Tubular Function and Acid-Base Balance
o Hormone Receptors and Signal Transduction
o GI Motility, Secretion, and Nutrient Absorption
COVER PAGE - 1
, SECTION 1 | Cell Physiology and Membrane Transport | Q1-Q20 | GMS 6440 Fundamentals Of Medical Phy
Q1 Question 1 of 100
A 45-year-old patient presents with muscle weakness after starting a new diuretic. Laboratory studies
reveal hypokalemia. The physician explains that the resting membrane potential of skeletal muscle is
determined primarily by the permeability of the cell membrane to potassium ions and the
concentration gradient maintained by the Na+/K+-ATPase pump. Which of the following best
describes the effect of severe hypokalemia on the resting membrane potential of skeletal muscle?
A. The resting membrane potential becomes more negative, making the cell hyperpolarized and less
excitable.
B. The resting membrane potential becomes less negative, causing depolarization and increased
excitability.
C. The resting membrane potential remains unchanged because the Na+/K+-ATPase pump compensates
for potassium shifts.
D. The resting membrane potential becomes zero as potassium equilibrium is reached across the
membrane.
Correct Answer: A
Rationale:
Severe hypokalemia increases the transmembrane potassium gradient, making the intracellular environment more
negative relative to extracellular fluid. This hyperpolarization moves the resting membrane potential further from
threshold, reducing excitability and causing muscle weakness.
Q2 Question 2 of 100
A researcher is studying ion channel kinetics in a cultured neuron. She observes that applying a
depolarizing voltage step opens voltage-gated sodium channels rapidly, but they inactivate within
milliseconds even though depolarization continues. Which structural domain of the voltage-gated
sodium channel is primarily responsible for this fast inactivation?
A. The S4 voltage sensor helices that detect membrane potential changes.
B. The intracellular loop between domains III and IV that acts as a hinged lid.
C. The pore loop (P-loop) containing the selectivity filter residues.
D. The extracellular N-terminal domain that modulates channel trafficking.
Correct Answer: B
Rationale:
Fast inactivation of voltage-gated sodium channels is mediated by the intracellular loop connecting domains III and IV,
which folds into the intracellular mouth of the pore like a hinged lid. The S4 helices detect voltage, the P-loop
determines ion selectivity, and the N-terminus is not involved in inactivation gating.
40 Fundamentals Of Medical Physiology Final Exam Questions With Correct Answers, 100% Guaranteed Pass || Complete A+ Guide - 2026/2027 | Passing Score: 80% | Pag
, SECTION 1 | Cell Physiology and Membrane Transport | Q1-Q20 | GMS 6440 Fundamentals Of Medical Phy
Q3 Question 3 of 100
A 62-year-old man with heart failure is treated with digoxin, which inhibits the Na+/K+-ATPase pump
in cardiac myocytes. The physician explains that this inhibition indirectly increases intracellular
calcium by altering the sodium gradient. Which transport mechanism is primarily responsible for this
secondary increase in cytosolic calcium concentration?
A. The sarcoplasmic reticulum Ca2+-ATPase (SERCA) pump, which sequesters calcium into the SR.
B. The Na+/Ca2+ exchanger (NCX), which normally extrudes calcium using the sodium gradient.
C. The plasma membrane Ca2+-ATPase (PMCA) pump, which directly pumps calcium out of the cell.
D. The voltage-gated L-type calcium channel, which allows calcium influx during depolarization.
Correct Answer: B
Rationale:
The Na+/Ca2+ exchanger normally uses the electrochemical sodium gradient to extrude calcium from the cell.
Digoxin-induced Na+/K+-ATPase inhibition raises intracellular sodium, reducing the sodium gradient and causing NCX
to operate in reverse or slow forward transport, thereby increasing intracellular calcium and contractility.
Q4 Question 4 of 100
A medical student is reviewing the differences between action potentials in skeletal muscle and
cardiac pacemaker cells. She notes that cardiac pacemaker cells in the sinoatrial node lack a stable
resting membrane potential. Which ionic current is primarily responsible for the spontaneous phase 4
depolarization that characterizes pacemaker automaticity?
A. The rapid influx of Na+ through voltage-gated sodium channels (INa).
B. The funny current (If), a mixed Na+/K+ inward current activated by hyperpolarization.
C. The sustained outward K+ current (IKs) that maintains repolarization.
D. The L-type calcium current (ICa-L) that drives the upstroke of the action potential.
Correct Answer: B
Rationale:
The funny current (If) is a hyperpolarization-activated mixed cation current (Na+/K+) carried primarily by HCN
channels. It slowly depolarizes the pacemaker cell during phase 4, bringing the membrane toward threshold. INa is
absent in nodal cells, IKs maintains plateau repolarization, and ICa-L drives the upstroke but does not initiate phase 4.
40 Fundamentals Of Medical Physiology Final Exam Questions With Correct Answers, 100% Guaranteed Pass || Complete A+ Guide - 2026/2027 | Passing Score: 80% | Pag
, SECTION 1 | Cell Physiology and Membrane Transport | Q1-Q20 | GMS 6440 Fundamentals Of Medical Phy
Q5 Question 5 of 100
A 28-year-old athlete collapses during a marathon and is found to have rhabdomyolysis. Laboratory
analysis shows markedly elevated serum creatine kinase and hyperkalemia. The emergency
physician explains that the elevated extracellular potassium can depolarize skeletal muscle
membranes. Which concept best explains why sustained depolarization from hyperkalemia
paradoxically causes muscle weakness rather than sustained contraction?
A. Voltage-gated sodium channels enter inactivated states and cannot recover at depolarized potentials.
B. The Na+/K+-ATPase pump is overwhelmed and stops functioning entirely.
C. Potassium channels open fully and hyperpolarize the membrane beyond resting potential.
D. Calcium channels become blocked, preventing excitation-contraction coupling.
Correct Answer: A
Rationale:
Sustained depolarization from hyperkalemia causes voltage-gated sodium channels to inactivate and enter a
refractory state. Because these channels cannot recover from inactivation at depolarized potentials, no new action
potentials can be generated, resulting in flaccid paralysis despite the depolarized membrane.
Q6 Question 6 of 100
A researcher is examining epithelial transport in the proximal tubule of the kidney. She observes that
glucose is reabsorbed against its concentration gradient from the tubular lumen into the epithelial
cell. Which transport mechanism correctly describes this process, and what ion provides the driving
force?
A. Facilitated diffusion via GLUT transporters, driven by the intracellular glucose concentration.
B. Secondary active transport via SGLT transporters, driven by the sodium electrochemical gradient.
C. Primary active transport via Na+/K+-ATPase, which directly pumps glucose against its gradient.
D. Osmosis through aquaporin channels, driven by the tubular osmotic gradient.
Correct Answer: B
Rationale:
Proximal tubular glucose reabsorption occurs via SGLT (sodium-glucose linked transporters), which are secondary
active symporters. They use the sodium electrochemical gradient established by basolateral Na+/K+-ATPase to
cotransport glucose uphill into the cell. GLUT transporters mediate passive facilitated diffusion, and Na+/K+-ATPase
does not transport glucose directly.
40 Fundamentals Of Medical Physiology Final Exam Questions With Correct Answers, 100% Guaranteed Pass || Complete A+ Guide - 2026/2027 | Passing Score: 80% | Pag
