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 boy is evaluated for recurrent respiratory
infections and chronic sinusitis. Electron microscopy of ciliated
respiratory epithelium demonstrates absent dynein arms within
microtubules. Which cellular process is most directly impaired
in this patient?
A. ATP generation through oxidative phosphorylation
B. Intracellular protein degradation by lysosomes
,C. Microtubule-mediated motility requiring ATP hydrolysis
D. Calcium-dependent exocytosis from the Golgi apparatus
Correct Answer: C
Rationale:
• Clinical Clue: Recurrent respiratory infections with absent
dynein arms suggests primary ciliary dyskinesia.
• Mechanism: Dynein is a motor protein that hydrolyzes ATP
to generate movement along microtubules.
• Why the Correct Answer Is Right: Ciliary beating depends
on ATP-driven dynein arm activity within the microtubular
axoneme.
• Why the Other Options Are Wrong:
o A: Mitochondrial ATP generation is not the primary
defect.
o B: Lysosomal degradation is unrelated to ciliary
movement.
o D: Exocytosis involves vesicle fusion, not dynein arm
dysfunction.
• Exam Trap: Confusing microtubules with actin-mediated
motility.
• High-Yield Clinical Correlation: Defective ciliary motility
predisposes to bronchiectasis, infertility, and situs
inversus.
, • Memory Anchor: “Dynein drives cilia.”
Q2. A researcher exposes cultured hepatocytes to a toxin that
disrupts rough endoplasmic reticulum function. Which
alteration would most likely develop first?
A. Impaired synthesis of secreted plasma proteins
B. Failure of oxidative phosphorylation
C. Reduced lysosomal acidification
D. Inability to generate spindle fibers during mitosis
Correct Answer: A
Rationale:
• Clinical Clue: Rough endoplasmic reticulum (RER) is
abundant in hepatocytes due to protein synthesis
demands.
• Mechanism: Ribosomes attached to the RER synthesize
membrane-bound and secreted proteins.
• Why the Correct Answer Is Right: Hepatic production of
albumin and clotting factors depends heavily on intact RER
function.
• Why the Other Options Are Wrong:
o B: Oxidative phosphorylation occurs in mitochondria.
o C: Lysosomal acidification depends on proton pumps.
o D: Spindle fibers are microtubule structures.
, • Exam Trap: Confusing smooth and rough ER functions.
• High-Yield Clinical Correlation: Hepatic injury commonly
reduces albumin synthesis before other manifestations
become evident.
• Memory Anchor: “Rough ER = ribosomes = exported
proteins.”
Q3. A patient with severe hypoxia develops rapidly declining
ATP levels within cardiac myocytes. Which membrane transport
abnormality most directly results from ATP depletion?
A. Increased facilitated diffusion of glucose
B. Failure of Na+/K+-ATPase activity
C. Enhanced receptor-mediated endocytosis
D. Increased passive diffusion of potassium into cells
Correct Answer: B
Rationale:
• Clinical Clue: ATP depletion in ischemic tissue disrupts
energy-dependent transport.
• Mechanism: The Na+/K+-ATPase requires ATP to maintain
ionic gradients.
• Why the Correct Answer Is Right: ATP depletion causes
intracellular sodium accumulation and cellular swelling.
• Why the Other Options Are Wrong:
The Biologic Basis for Disease in Adults
and Children
9th Edition
Author(s)Julia Rogers
TEST BANK
Q1. A 6-year-old boy is evaluated for recurrent respiratory
infections and chronic sinusitis. Electron microscopy of ciliated
respiratory epithelium demonstrates absent dynein arms within
microtubules. Which cellular process is most directly impaired
in this patient?
A. ATP generation through oxidative phosphorylation
B. Intracellular protein degradation by lysosomes
,C. Microtubule-mediated motility requiring ATP hydrolysis
D. Calcium-dependent exocytosis from the Golgi apparatus
Correct Answer: C
Rationale:
• Clinical Clue: Recurrent respiratory infections with absent
dynein arms suggests primary ciliary dyskinesia.
• Mechanism: Dynein is a motor protein that hydrolyzes ATP
to generate movement along microtubules.
• Why the Correct Answer Is Right: Ciliary beating depends
on ATP-driven dynein arm activity within the microtubular
axoneme.
• Why the Other Options Are Wrong:
o A: Mitochondrial ATP generation is not the primary
defect.
o B: Lysosomal degradation is unrelated to ciliary
movement.
o D: Exocytosis involves vesicle fusion, not dynein arm
dysfunction.
• Exam Trap: Confusing microtubules with actin-mediated
motility.
• High-Yield Clinical Correlation: Defective ciliary motility
predisposes to bronchiectasis, infertility, and situs
inversus.
, • Memory Anchor: “Dynein drives cilia.”
Q2. A researcher exposes cultured hepatocytes to a toxin that
disrupts rough endoplasmic reticulum function. Which
alteration would most likely develop first?
A. Impaired synthesis of secreted plasma proteins
B. Failure of oxidative phosphorylation
C. Reduced lysosomal acidification
D. Inability to generate spindle fibers during mitosis
Correct Answer: A
Rationale:
• Clinical Clue: Rough endoplasmic reticulum (RER) is
abundant in hepatocytes due to protein synthesis
demands.
• Mechanism: Ribosomes attached to the RER synthesize
membrane-bound and secreted proteins.
• Why the Correct Answer Is Right: Hepatic production of
albumin and clotting factors depends heavily on intact RER
function.
• Why the Other Options Are Wrong:
o B: Oxidative phosphorylation occurs in mitochondria.
o C: Lysosomal acidification depends on proton pumps.
o D: Spindle fibers are microtubule structures.
, • Exam Trap: Confusing smooth and rough ER functions.
• High-Yield Clinical Correlation: Hepatic injury commonly
reduces albumin synthesis before other manifestations
become evident.
• Memory Anchor: “Rough ER = ribosomes = exported
proteins.”
Q3. A patient with severe hypoxia develops rapidly declining
ATP levels within cardiac myocytes. Which membrane transport
abnormality most directly results from ATP depletion?
A. Increased facilitated diffusion of glucose
B. Failure of Na+/K+-ATPase activity
C. Enhanced receptor-mediated endocytosis
D. Increased passive diffusion of potassium into cells
Correct Answer: B
Rationale:
• Clinical Clue: ATP depletion in ischemic tissue disrupts
energy-dependent transport.
• Mechanism: The Na+/K+-ATPase requires ATP to maintain
ionic gradients.
• Why the Correct Answer Is Right: ATP depletion causes
intracellular sodium accumulation and cellular swelling.
• Why the Other Options Are Wrong:
