McCance & Huether’s Pathophysiology
The Biologic Basis for Disease in Adults
and Children
9th Edition
Author(s)Julia Rogers
TEST BANK
Q1. A 6-year-old child is diagnosed with a hereditary disorder
characterized by defective dynein arms within respiratory
epithelial cilia. Chronic sinusitis, recurrent otitis media, and
bronchiectasis develop over time. The impaired mucociliary
clearance most directly results from dysfunction of which
cellular structure?
A. Intermediate filaments
B. Rough endoplasmic reticulum
,C. Microtubules
D. Microfilaments
E. Golgi apparatus
Correct Answer: C
Rationale:
• Clinical Clue: Recurrent respiratory infections with
defective ciliary movement indicate impaired axonemal
function.
• Mechanism: Dynein arms interact with microtubules
within cilia to generate coordinated movement.
• Why the Correct Answer Is Right: Microtubules form the
structural core of cilia and are essential for mucociliary
transport.
• Why the Other Options Are Wrong:
o Intermediate filaments maintain tensile strength but
do not mediate ciliary motility.
o Rough ER synthesizes proteins rather than driving
movement.
o Microfilaments primarily support contraction and
shape changes.
o Golgi apparatus modifies and packages proteins.
• Exam Trap: Confusing cytoskeletal elements involved in
movement versus structural stability.
, • High-Yield Clinical Correlation: Primary ciliary dyskinesia
often presents with situs inversus due to impaired
embryonic ciliary function.
• Memory Anchor: “Cilia glide on microtubule tracks.”
Q2. A patient with severe alcoholism develops hepatocyte
swelling after acute hypoxic injury. Microscopy demonstrates
plasma membrane blebbing and intracellular sodium
accumulation. Which pathophysiologic change best accounts
for these findings?
A. Increased lysosomal proteolysis
B. Failure of ATP-dependent membrane pumps
C. Excessive mitochondrial calcium export
D. Enhanced ribosomal protein synthesis
E. Activation of nuclear DNA repair enzymes
Correct Answer: B
Rationale:
• Clinical Clue: Cellular swelling after hypoxia reflects early
reversible injury.
• Mechanism: ATP depletion disables Na+/K+-ATPase
activity, causing sodium and water influx.
• Why the Correct Answer Is Right: Membrane pump failure
is a hallmark of reversible hypoxic cell injury.
• Why the Other Options Are Wrong:
, o Lysosomal proteolysis occurs later during irreversible
injury.
o Mitochondrial calcium export is reduced, not
increased.
o Protein synthesis declines during ATP depletion.
o DNA repair does not explain osmotic swelling.
• Exam Trap: Mistaking reversible swelling for irreversible
necrosis.
• High-Yield Clinical Correlation: Hydropic cellular swelling is
one of the earliest morphologic signs of ischemic injury.
• Memory Anchor: “Low ATP lets sodium stay.”
Q3. A researcher observes that a signaling molecule binds a
membrane receptor, activates adenylate cyclase, and rapidly
increases intracellular cyclic AMP. Which process most directly
follows this signaling event?
A. Activation of protein kinase A
B. Cleavage of genomic DNA
C. Polymerization of actin filaments
D. Direct opening of voltage-gated calcium channels
E. Hydrolysis of membrane phospholipids by lysosomes
Correct Answer: A
Rationale:
The Biologic Basis for Disease in Adults
and Children
9th Edition
Author(s)Julia Rogers
TEST BANK
Q1. A 6-year-old child is diagnosed with a hereditary disorder
characterized by defective dynein arms within respiratory
epithelial cilia. Chronic sinusitis, recurrent otitis media, and
bronchiectasis develop over time. The impaired mucociliary
clearance most directly results from dysfunction of which
cellular structure?
A. Intermediate filaments
B. Rough endoplasmic reticulum
,C. Microtubules
D. Microfilaments
E. Golgi apparatus
Correct Answer: C
Rationale:
• Clinical Clue: Recurrent respiratory infections with
defective ciliary movement indicate impaired axonemal
function.
• Mechanism: Dynein arms interact with microtubules
within cilia to generate coordinated movement.
• Why the Correct Answer Is Right: Microtubules form the
structural core of cilia and are essential for mucociliary
transport.
• Why the Other Options Are Wrong:
o Intermediate filaments maintain tensile strength but
do not mediate ciliary motility.
o Rough ER synthesizes proteins rather than driving
movement.
o Microfilaments primarily support contraction and
shape changes.
o Golgi apparatus modifies and packages proteins.
• Exam Trap: Confusing cytoskeletal elements involved in
movement versus structural stability.
, • High-Yield Clinical Correlation: Primary ciliary dyskinesia
often presents with situs inversus due to impaired
embryonic ciliary function.
• Memory Anchor: “Cilia glide on microtubule tracks.”
Q2. A patient with severe alcoholism develops hepatocyte
swelling after acute hypoxic injury. Microscopy demonstrates
plasma membrane blebbing and intracellular sodium
accumulation. Which pathophysiologic change best accounts
for these findings?
A. Increased lysosomal proteolysis
B. Failure of ATP-dependent membrane pumps
C. Excessive mitochondrial calcium export
D. Enhanced ribosomal protein synthesis
E. Activation of nuclear DNA repair enzymes
Correct Answer: B
Rationale:
• Clinical Clue: Cellular swelling after hypoxia reflects early
reversible injury.
• Mechanism: ATP depletion disables Na+/K+-ATPase
activity, causing sodium and water influx.
• Why the Correct Answer Is Right: Membrane pump failure
is a hallmark of reversible hypoxic cell injury.
• Why the Other Options Are Wrong:
, o Lysosomal proteolysis occurs later during irreversible
injury.
o Mitochondrial calcium export is reduced, not
increased.
o Protein synthesis declines during ATP depletion.
o DNA repair does not explain osmotic swelling.
• Exam Trap: Mistaking reversible swelling for irreversible
necrosis.
• High-Yield Clinical Correlation: Hydropic cellular swelling is
one of the earliest morphologic signs of ischemic injury.
• Memory Anchor: “Low ATP lets sodium stay.”
Q3. A researcher observes that a signaling molecule binds a
membrane receptor, activates adenylate cyclase, and rapidly
increases intracellular cyclic AMP. Which process most directly
follows this signaling event?
A. Activation of protein kinase A
B. Cleavage of genomic DNA
C. Polymerization of actin filaments
D. Direct opening of voltage-gated calcium channels
E. Hydrolysis of membrane phospholipids by lysosomes
Correct Answer: A
Rationale:
