McCance & Huether’s Pathophysiology
The Biologic Basis for Disease in Adults
and Children
9th Edition
Author(s)Julia Rogers
TEST BANK
Q1. A researcher exposes hepatocytes to a toxin that selectively
disrupts rough endoplasmic reticulum function. Several hours
later, the cells demonstrate impaired secretion of plasma
proteins despite preserved ATP production. This finding is best
explained by failure of which cellular process?
A. Oxidative phosphorylation
B. Ribosomal protein synthesis and posttranslational processing
,C. β-oxidation of fatty acids
D. Lysosomal hydrolysis of intracellular debris
Correct Answer: B
Rationale:
• Clinical Clue: Impaired protein secretion with preserved
energy production points to defective synthetic rather
than mitochondrial function.
• Mechanism: Rough endoplasmic reticulum (RER) contains
ribosome-studded membranes responsible for synthesis
and initial modification of secretory and membrane
proteins.
• Why the Correct Answer Is Right: Plasma proteins require
translation on membrane-bound ribosomes and
processing through the RER before export.
• Why the Other Options Are Wrong:
o A. Oxidative phosphorylation primarily occurs in
mitochondria and would reduce ATP generation.
o C. β-oxidation also occurs in mitochondria and
peroxisomes, not RER.
o D. Lysosomal digestion affects degradation rather
than synthesis of plasma proteins.
• Exam Trap: Confusing free ribosomes with rough ER-
associated ribosomes. Secreted proteins are synthesized
on RER-bound ribosomes.
, • High-Yield Clinical Correlation: Disorders affecting RER
function often impair antibody and hormone production.
• Memory Anchor: “Rough ER = ribosomes = exported
proteins.”
Q2. A patient with chronic alcohol use develops hepatocellular
enlargement associated with increased detoxification enzyme
activity. Microscopy most likely demonstrates proliferation of
which organelle?
A. Golgi apparatus
B. Smooth endoplasmic reticulum
C. Nucleolus
D. Lysosome
Correct Answer: B
Rationale:
• Clinical Clue: Chronic toxin exposure induces adaptive
detoxification mechanisms in hepatocytes.
• Mechanism: Smooth endoplasmic reticulum (SER) contains
cytochrome P450 enzymes involved in drug and toxin
metabolism.
• Why the Correct Answer Is Right: SER hypertrophy occurs
in response to prolonged exposure to alcohol,
barbiturates, and other xenobiotics.
• Why the Other Options Are Wrong:
, o A. Golgi apparatus modifies and packages proteins
rather than detoxifying chemicals.
o C. The nucleolus synthesizes rRNA.
o D. Lysosomes degrade cellular debris and pathogens.
• Exam Trap: Associating all protein-processing functions
with Golgi rather than recognizing SER-mediated
detoxification.
• High-Yield Clinical Correlation: Increased SER activity
contributes to drug tolerance through accelerated
metabolism.
• Memory Anchor: “Smooth ER smooths out toxins.”
Q3. A child with a genetic defect in dynein arms experiences
recurrent respiratory infections and infertility. The underlying
cellular abnormality most directly involves impaired function of
which structure?
A. Microfilaments
B. Intermediate filaments
C. Microtubules
D. Desmosomes
Correct Answer: C
Rationale:
The Biologic Basis for Disease in Adults
and Children
9th Edition
Author(s)Julia Rogers
TEST BANK
Q1. A researcher exposes hepatocytes to a toxin that selectively
disrupts rough endoplasmic reticulum function. Several hours
later, the cells demonstrate impaired secretion of plasma
proteins despite preserved ATP production. This finding is best
explained by failure of which cellular process?
A. Oxidative phosphorylation
B. Ribosomal protein synthesis and posttranslational processing
,C. β-oxidation of fatty acids
D. Lysosomal hydrolysis of intracellular debris
Correct Answer: B
Rationale:
• Clinical Clue: Impaired protein secretion with preserved
energy production points to defective synthetic rather
than mitochondrial function.
• Mechanism: Rough endoplasmic reticulum (RER) contains
ribosome-studded membranes responsible for synthesis
and initial modification of secretory and membrane
proteins.
• Why the Correct Answer Is Right: Plasma proteins require
translation on membrane-bound ribosomes and
processing through the RER before export.
• Why the Other Options Are Wrong:
o A. Oxidative phosphorylation primarily occurs in
mitochondria and would reduce ATP generation.
o C. β-oxidation also occurs in mitochondria and
peroxisomes, not RER.
o D. Lysosomal digestion affects degradation rather
than synthesis of plasma proteins.
• Exam Trap: Confusing free ribosomes with rough ER-
associated ribosomes. Secreted proteins are synthesized
on RER-bound ribosomes.
, • High-Yield Clinical Correlation: Disorders affecting RER
function often impair antibody and hormone production.
• Memory Anchor: “Rough ER = ribosomes = exported
proteins.”
Q2. A patient with chronic alcohol use develops hepatocellular
enlargement associated with increased detoxification enzyme
activity. Microscopy most likely demonstrates proliferation of
which organelle?
A. Golgi apparatus
B. Smooth endoplasmic reticulum
C. Nucleolus
D. Lysosome
Correct Answer: B
Rationale:
• Clinical Clue: Chronic toxin exposure induces adaptive
detoxification mechanisms in hepatocytes.
• Mechanism: Smooth endoplasmic reticulum (SER) contains
cytochrome P450 enzymes involved in drug and toxin
metabolism.
• Why the Correct Answer Is Right: SER hypertrophy occurs
in response to prolonged exposure to alcohol,
barbiturates, and other xenobiotics.
• Why the Other Options Are Wrong:
, o A. Golgi apparatus modifies and packages proteins
rather than detoxifying chemicals.
o C. The nucleolus synthesizes rRNA.
o D. Lysosomes degrade cellular debris and pathogens.
• Exam Trap: Associating all protein-processing functions
with Golgi rather than recognizing SER-mediated
detoxification.
• High-Yield Clinical Correlation: Increased SER activity
contributes to drug tolerance through accelerated
metabolism.
• Memory Anchor: “Smooth ER smooths out toxins.”
Q3. A child with a genetic defect in dynein arms experiences
recurrent respiratory infections and infertility. The underlying
cellular abnormality most directly involves impaired function of
which structure?
A. Microfilaments
B. Intermediate filaments
C. Microtubules
D. Desmosomes
Correct Answer: C
Rationale:
