Guide 2025–2026, Covering Cellular Physiology and Homeostasis, Membrane
Transport and Cell Signaling Mechanisms, Nervous System Function and
Neurophysiology, Skeletal and Muscular Physiology, Cardiovascular System
Regulation and Hemodynamics, Respiratory Physiology and Gas Exchange
Processes, Renal Function and Fluid-Electrolyte Balance, Endocrine System
Hormonal Control Mechanisms, Gastrointestinal Physiology and Nutrient
Absorption, Reproductive Physiology and Human Development, Immune
System Function and Defense Mechanisms, Acid-Base Regulation and
Metabolic Integration, Practice Questions with Verified Answers and Detailed
Explanations, Clinical Physiology Case Studies, Step-by-Step Physiological
Frameworks, and Proven Strategies to Successfully Master Vander’s Human
Physiology 14th Edition
Question 1: What primarily establishes the resting membrane potential in mammalian cells?
A. Equal Na+/K+ permeability
B. High K+ permeability and Na+/K+ ATPase
C. High Na+ permeability
D. Active Cl- transport
CORRECT ANSWER: B. High K+ permeability and Na+/K+ ATPase
Rationale: High K+ leak channel permeability allows K+ efflux, creating a negative interior, while
the Na+/K+ ATPase maintains the necessary ionic gradients.
Question 2: Which ion is primarily responsible for the depolarization phase of an action
potential in a neuron?
A. K+
B. Ca2+
C. Na+
D. Cl-
CORRECT ANSWER: C. Na+
Rationale: Voltage-gated Na+ channels open rapidly upon threshold depolarization, allowing
Na+ influx which drives the membrane potential toward the Na+ equilibrium potential.
,Question 3: What is the primary function of the Na+/K+ ATPase pump?
A. Generate action potentials
B. Maintain ionic concentration gradients
C. Open voltage-gated channels
D. Synthesize neurotransmitters
CORRECT ANSWER: B. Maintain ionic concentration gradients
Rationale: The pump actively transports 3 Na+ out and 2 K+ into the cell using ATP, maintaining
the electrochemical gradients essential for excitability.
Question 4: Which of the following best describes absolute refractory period?
A. Time when only strong stimuli can trigger an AP
B. Time when no stimulus can trigger a new AP
C. Time when K+ channels are closed
D. Time when Na+ channels are resting
CORRECT ANSWER: B. Time when no stimulus can trigger a new AP
Rationale: During the absolute refractory period, voltage-gated Na+ channels are inactivated
and cannot reopen, preventing any new action potential.
Question 5: How does myelination affect nerve conduction velocity?
A. Decreases it by increasing capacitance
B. Increases it via saltatory conduction
C. Decreases it by blocking ion flow
D. Has no effect on velocity
CORRECT ANSWER: B. Increases it via saltatory conduction
Rationale: Myelin insulates the axon, forcing action potentials to jump between Nodes of
Ranvier, which significantly increases conduction speed.
Question 6: What triggers neurotransmitter release at the presynaptic terminal?
A. Na+ influx
B. K+ efflux
C. Ca2+ influx
,D. Cl- influx
CORRECT ANSWER: C. Ca2+ influx
Rationale: Depolarization opens voltage-gated Ca2+ channels; the resulting Ca2+ influx causes
synaptic vesicles to fuse with the membrane and release neurotransmitter.
Question 7: Which neurotransmitter is the primary excitatory transmitter in the CNS?
A. GABA
B. Glycine
C. Glutamate
D. Dopamine
CORRECT ANSWER: C. Glutamate
Rationale: Glutamate is the major excitatory neurotransmitter in the brain, acting on receptors
like NMDA and AMPA to depolarize postsynaptic neurons.
Question 8: What is the primary effect of GABA in the central nervous system?
A. Excitatory depolarization
B. Inhibitory hyperpolarization
C. Modulation of pain
D. Stimulation of muscle contraction
CORRECT ANSWER: B. Inhibitory hyperpolarization
Rationale: GABA opens Cl- channels, causing Cl- influx which hyperpolarizes the postsynaptic
membrane, making it less likely to fire an action potential.
Question 9: Which receptor type is responsible for fast synaptic transmission?
A. G-protein coupled receptors
B. Ionotropic receptors
C. Metabotropic receptors
D. Intracellular receptors
CORRECT ANSWER: B. Ionotropic receptors
Rationale: Ionotropic receptors are ligand-gated ion channels that open directly upon
neurotransmitter binding, allowing rapid ion flow and fast synaptic transmission.
, Question 10: What is the primary function of astrocytes in the CNS?
A. Phagocytosis of debris
B. Formation of myelin in PNS
C. Support, blood-brain barrier, and ion buffering
D. Production of cerebrospinal fluid
CORRECT ANSWER: C. Support, blood-brain barrier, and ion buffering
Rationale: Astrocytes provide structural support, regulate extracellular ion concentrations,
contribute to the blood-brain barrier, and modulate synaptic transmission.
Question 11: Which glial cell forms myelin in the peripheral nervous system?
A. Oligodendrocytes
B. Schwann cells
C. Microglia
D. Ependymal cells
CORRECT ANSWER: B. Schwann cells
Rationale: Schwann cells wrap around PNS axons to form the myelin sheath, whereas
oligodendrocytes perform this function in the CNS.
Question 12: What is the primary role of microglia?
A. Nutrient transport
B. Immune defense and phagocytosis
C. CSF production
D. Synaptic insulation
CORRECT ANSWER: B. Immune defense and phagocytosis
Rationale: Microglia act as the primary immune cells of the CNS, scavenging for plaques,
damaged neurons, and infectious agents.
Question 13: Which ion is primarily responsible for repolarization of the action potential?
A. Na+
B. Ca2+
C. K+