Understanding Pathophysiology
8th Edition
Author(s)Sue E. Huether
TEST BANK
Q1. A researcher observes a mutation that disrupts integrin-
mediated anchoring of epithelial cells to the basement
membrane. A patient develops blistering of the skin with
minimal trauma. Which pathophysiologic process most directly
explains the tissue fragility?
A. Loss of tight junction barrier function
B. Impaired desmosomal adhesion between cells
C. Failure of cell–matrix adhesion signaling
D. Reduced gap junction ion exchange
E. Increased cadherin-mediated adhesion
Correct Answer: C
,Rationale:
Clinical Clue: Blistering with minimal trauma suggests defective
anchoring to extracellular matrix.
Mechanism: Integrins mediate cell–matrix adhesion and
transduce survival/mechanical signals.
Why the Correct Answer Is Right: Loss of integrin function
disrupts attachment to the basement membrane, leading to
mechanical instability.
Why the Other Options Are Wrong: Tight junctions regulate
permeability (A); desmosomes link cells, not matrix (B); gap
junctions allow ion transfer (D); cadherins mediate cell–cell
adhesion (E).
Exam Trap: Confusing cell–cell adhesion with cell–matrix
adhesion.
High-Yield Clinical Correlation: Defects resemble forms of
epidermolysis bullosa.
Q2. A patient with severe dehydration develops cellular
shrinkage. Which transport mechanism is primarily responsible
for this change?
A. Facilitated diffusion of glucose
B. Osmosis driven by extracellular hypertonicity
C. Active transport via Na⁺/K⁺ ATPase
D. Endocytosis of extracellular fluid
E. Secondary active transport of sodium
Correct Answer: B
,Rationale:
Clinical Clue: Dehydration → hypertonic extracellular fluid.
Mechanism: Water moves across semipermeable membranes
down osmotic gradients.
Why the Correct Answer Is Right: Hypertonic extracellular
environment draws water out of cells via osmosis.
Why the Other Options Are Wrong: Glucose transport does not
explain water loss (A); Na⁺/K⁺ pump maintains gradients but
not acute shrinkage (C); endocytosis is vesicular (D); secondary
transport moves solutes (E).
Exam Trap: Attributing volume changes to ion pumps rather
than osmotic gradients.
High-Yield Clinical Correlation: Cellular dehydration contributes
to neurologic symptoms in hypernatremia.
Q3. A toxin inhibits mitochondrial oxidative phosphorylation.
Affected cells accumulate lactate and demonstrate decreased
ATP. Which cellular process is most immediately impaired?
A. DNA replication
B. Protein synthesis
C. Active membrane transport
D. Lipid storage
E. Glycogen breakdown
Correct Answer: C
, Rationale:
Clinical Clue: ATP depletion from mitochondrial dysfunction.
Mechanism: ATP is required for energy-dependent processes.
Why the Correct Answer Is Right: Active transport (e.g., Na⁺/K⁺
ATPase) fails first with ATP depletion.
Why the Other Options Are Wrong: DNA replication and protein
synthesis are impaired later (A, B); lipid storage not
immediately ATP-dependent (D); glycogen breakdown may
increase initially (E).
Exam Trap: Assuming all processes fail simultaneously.
High-Yield Clinical Correlation: Pump failure leads to cellular
swelling and early reversible injury.
Q4. A mutation disrupts gap junction formation in cardiac
myocytes. Which physiologic change best accounts for the
resulting arrhythmia?
A. Impaired electrical coupling between cells
B. Loss of structural integrity of myocardium
C. Increased extracellular calcium influx
D. Enhanced autonomic stimulation
E. Decreased ATP production
Correct Answer: A
Rationale:
Clinical Clue: Gap junction defect in cardiac tissue.
Mechanism: Gap junctions allow direct ion flow for
8th Edition
Author(s)Sue E. Huether
TEST BANK
Q1. A researcher observes a mutation that disrupts integrin-
mediated anchoring of epithelial cells to the basement
membrane. A patient develops blistering of the skin with
minimal trauma. Which pathophysiologic process most directly
explains the tissue fragility?
A. Loss of tight junction barrier function
B. Impaired desmosomal adhesion between cells
C. Failure of cell–matrix adhesion signaling
D. Reduced gap junction ion exchange
E. Increased cadherin-mediated adhesion
Correct Answer: C
,Rationale:
Clinical Clue: Blistering with minimal trauma suggests defective
anchoring to extracellular matrix.
Mechanism: Integrins mediate cell–matrix adhesion and
transduce survival/mechanical signals.
Why the Correct Answer Is Right: Loss of integrin function
disrupts attachment to the basement membrane, leading to
mechanical instability.
Why the Other Options Are Wrong: Tight junctions regulate
permeability (A); desmosomes link cells, not matrix (B); gap
junctions allow ion transfer (D); cadherins mediate cell–cell
adhesion (E).
Exam Trap: Confusing cell–cell adhesion with cell–matrix
adhesion.
High-Yield Clinical Correlation: Defects resemble forms of
epidermolysis bullosa.
Q2. A patient with severe dehydration develops cellular
shrinkage. Which transport mechanism is primarily responsible
for this change?
A. Facilitated diffusion of glucose
B. Osmosis driven by extracellular hypertonicity
C. Active transport via Na⁺/K⁺ ATPase
D. Endocytosis of extracellular fluid
E. Secondary active transport of sodium
Correct Answer: B
,Rationale:
Clinical Clue: Dehydration → hypertonic extracellular fluid.
Mechanism: Water moves across semipermeable membranes
down osmotic gradients.
Why the Correct Answer Is Right: Hypertonic extracellular
environment draws water out of cells via osmosis.
Why the Other Options Are Wrong: Glucose transport does not
explain water loss (A); Na⁺/K⁺ pump maintains gradients but
not acute shrinkage (C); endocytosis is vesicular (D); secondary
transport moves solutes (E).
Exam Trap: Attributing volume changes to ion pumps rather
than osmotic gradients.
High-Yield Clinical Correlation: Cellular dehydration contributes
to neurologic symptoms in hypernatremia.
Q3. A toxin inhibits mitochondrial oxidative phosphorylation.
Affected cells accumulate lactate and demonstrate decreased
ATP. Which cellular process is most immediately impaired?
A. DNA replication
B. Protein synthesis
C. Active membrane transport
D. Lipid storage
E. Glycogen breakdown
Correct Answer: C
, Rationale:
Clinical Clue: ATP depletion from mitochondrial dysfunction.
Mechanism: ATP is required for energy-dependent processes.
Why the Correct Answer Is Right: Active transport (e.g., Na⁺/K⁺
ATPase) fails first with ATP depletion.
Why the Other Options Are Wrong: DNA replication and protein
synthesis are impaired later (A, B); lipid storage not
immediately ATP-dependent (D); glycogen breakdown may
increase initially (E).
Exam Trap: Assuming all processes fail simultaneously.
High-Yield Clinical Correlation: Pump failure leads to cellular
swelling and early reversible injury.
Q4. A mutation disrupts gap junction formation in cardiac
myocytes. Which physiologic change best accounts for the
resulting arrhythmia?
A. Impaired electrical coupling between cells
B. Loss of structural integrity of myocardium
C. Increased extracellular calcium influx
D. Enhanced autonomic stimulation
E. Decreased ATP production
Correct Answer: A
Rationale:
Clinical Clue: Gap junction defect in cardiac tissue.
Mechanism: Gap junctions allow direct ion flow for
