42202 A PHYSIOLOGY Friday, May 1, 2026 08:30am - 11:30am In Person HOA
160 CAMPBELL PHIL (philc).carnegie mellon university
42202 A PHYSIOLOGY Final Exam Review
Friday, May 1, 2026 | 08:30am - 11:30am | HOA 160 | PROF. PHIL CAMPBELL
SECTION 1: CELLULAR PHYSIOLOGY & MEMBRANE TRANSPORT (Qs 1-25)
1. What is the primary function of the sodium-potassium pump?
A) To transport sodium into the cell and potassium out of the cell
B) To maintain resting membrane potential by pumping 3 Na⁺ out and 2 K⁺ in
C) To generate ATP for cellular processes
D) To facilitate diffusion of glucose across the membrane
Answer: B
Rationale: The sodium-potassium pump (Na⁺/K⁺-ATPase) actively transports three
sodium ions out of the cell and two potassium ions into the cell against their
,concentration gradients. This establishes and maintains the electrochemical
gradient essential for action potentials and secondary active transport .
2. Which part of the neuron receives incoming signals from other neurons?
A) Axon hillock
B) Axon terminal
C) Dendrites
D) Myelin sheath
Answer: C
Rationale: Dendrites are the branched projections of a neuron that contain
receptor sites for neurotransmitters released by other neurons. They receive
incoming signals and transmit them toward the cell body .
3. Which ion is primarily responsible for initiating an action potential by entering
the neuron?
A) Potassium (K⁺)
,B) Calcium (Ca²⁺)
C) Sodium (Na⁺)
D) Chloride (Cl⁻)
Answer: C
Rationale: Depolarization occurs when voltage-gated sodium channels open,
allowing Na⁺ to rush into the cell down its electrochemical gradient. This influx
makes the membrane potential less negative, initiating the action potential .
4. During repolarization, which ion exits the neuron to restore the negative
resting membrane potential?
A) Sodium (Na⁺)
B) Calcium (Ca²⁺)
C) Potassium (K⁺)
D) Chloride (Cl⁻)
Answer: C
, Rationale: Voltage-gated potassium channels open during repolarization, allowing
K⁺ to exit the cell. This efflux of positive charge makes the inside of the cell more
negative again, returning toward resting potential .
5. What is the role of calcium ions (Ca²⁺) at the synaptic terminal?
A) To directly cause postsynaptic depolarization
B) To trigger neurotransmitter release from synaptic vesicles
C) To break down acetylcholine in the synaptic cleft
D) To bind to receptors on the postsynaptic membrane
Answer: B
Rationale: When an action potential reaches the synaptic terminal, voltage-gated
calcium channels open. The influx of Ca²⁺ causes synaptic vesicles to fuse with the
presynaptic membrane, releasing neurotransmitters into the synaptic cleft .
6. What is the main function of the myelin sheath?
A) To produce cerebrospinal fluid
160 CAMPBELL PHIL (philc).carnegie mellon university
42202 A PHYSIOLOGY Final Exam Review
Friday, May 1, 2026 | 08:30am - 11:30am | HOA 160 | PROF. PHIL CAMPBELL
SECTION 1: CELLULAR PHYSIOLOGY & MEMBRANE TRANSPORT (Qs 1-25)
1. What is the primary function of the sodium-potassium pump?
A) To transport sodium into the cell and potassium out of the cell
B) To maintain resting membrane potential by pumping 3 Na⁺ out and 2 K⁺ in
C) To generate ATP for cellular processes
D) To facilitate diffusion of glucose across the membrane
Answer: B
Rationale: The sodium-potassium pump (Na⁺/K⁺-ATPase) actively transports three
sodium ions out of the cell and two potassium ions into the cell against their
,concentration gradients. This establishes and maintains the electrochemical
gradient essential for action potentials and secondary active transport .
2. Which part of the neuron receives incoming signals from other neurons?
A) Axon hillock
B) Axon terminal
C) Dendrites
D) Myelin sheath
Answer: C
Rationale: Dendrites are the branched projections of a neuron that contain
receptor sites for neurotransmitters released by other neurons. They receive
incoming signals and transmit them toward the cell body .
3. Which ion is primarily responsible for initiating an action potential by entering
the neuron?
A) Potassium (K⁺)
,B) Calcium (Ca²⁺)
C) Sodium (Na⁺)
D) Chloride (Cl⁻)
Answer: C
Rationale: Depolarization occurs when voltage-gated sodium channels open,
allowing Na⁺ to rush into the cell down its electrochemical gradient. This influx
makes the membrane potential less negative, initiating the action potential .
4. During repolarization, which ion exits the neuron to restore the negative
resting membrane potential?
A) Sodium (Na⁺)
B) Calcium (Ca²⁺)
C) Potassium (K⁺)
D) Chloride (Cl⁻)
Answer: C
, Rationale: Voltage-gated potassium channels open during repolarization, allowing
K⁺ to exit the cell. This efflux of positive charge makes the inside of the cell more
negative again, returning toward resting potential .
5. What is the role of calcium ions (Ca²⁺) at the synaptic terminal?
A) To directly cause postsynaptic depolarization
B) To trigger neurotransmitter release from synaptic vesicles
C) To break down acetylcholine in the synaptic cleft
D) To bind to receptors on the postsynaptic membrane
Answer: B
Rationale: When an action potential reaches the synaptic terminal, voltage-gated
calcium channels open. The influx of Ca²⁺ causes synaptic vesicles to fuse with the
presynaptic membrane, releasing neurotransmitters into the synaptic cleft .
6. What is the main function of the myelin sheath?
A) To produce cerebrospinal fluid
