Understanding Pathophysiology
8th Edition
Author(s)Sue E. Huether
TEST BANK
Q1. A 4-year-old boy presents with recurrent bacterial
infections, poor wound healing, and delayed separation of the
umbilical cord after birth. Flow cytometry demonstrates absent
β2-integrin expression on neutrophils. The patient’s recurrent
infections are most directly related to failure of which cellular
process?
A. Intracellular lysosomal degradation
B. Endothelial transcytosis of immunoglobulins
C. Leukocyte adhesion to vascular endothelium
D. Neutrophil oxidative burst generation
E. Bone marrow myeloid differentiation
,Correct Answer: C
Rationale:
Clinical Clue:
Delayed umbilical cord separation and recurrent bacterial
infections strongly suggest leukocyte adhesion deficiency.
Mechanism:
β2-integrins are required for firm leukocyte adhesion to
endothelial ICAM molecules during extravasation.
Why the Correct Answer Is Right:
Without functional integrins, neutrophils cannot migrate
effectively from blood into infected tissues despite normal
production.
Why the Other Options Are Wrong:
A. Lysosomal degradation remains intact.
B. Immunoglobulin transport is unrelated to neutrophil
migration.
D. Oxidative burst defects occur in chronic granulomatous
disease.
E. Myeloid differentiation defects cause pancytopenia rather
than adhesion failure.
Exam Trap (common misconception tested):
Confusing leukocyte migration defects with neutrophil killing
defects.
,High-Yield Clinical Correlation:
Adhesion molecule defects produce marked neutrophilia
because leukocytes remain trapped in circulation.
Q2. A researcher inhibits Na+/K+-ATPase activity in cultured
cardiac myocytes. Within minutes, cells begin swelling. The
earliest mechanism responsible for this morphologic change is
best explained by:
A. Increased intracellular oncotic pressure from protein
synthesis
B. Osmotic influx of water following intracellular sodium
accumulation
C. Mitochondrial calcium precipitation causing membrane
rupture
D. Increased lysosomal permeability with autodigestion
E. Activation of caspase-mediated apoptosis pathways
Correct Answer: B
Rationale:
Clinical Clue:
Acute inhibition of Na+/K+-ATPase causes rapid cellular
swelling.
Mechanism:
ATP-dependent sodium extrusion fails, increasing intracellular
sodium concentration and drawing water into the cell.
, Why the Correct Answer Is Right:
Loss of membrane ion gradients produces osmotic cellular
edema, an early reversible injury.
Why the Other Options Are Wrong:
A. Protein synthesis is not the immediate driver.
C. Calcium injury occurs later.
D. Lysosomal rupture characterizes severe irreversible injury.
E. Apoptosis does not initially produce swelling.
Exam Trap (common misconception tested):
Confusing reversible hydropic swelling with irreversible necrotic
injury.
High-Yield Clinical Correlation:
Cellular swelling is one of the earliest morphologic
manifestations of ATP depletion.
Q3. A woman with metastatic breast carcinoma develops
progressive cachexia despite adequate caloric intake. Biopsy of
skeletal muscle demonstrates increased ubiquitin-proteasome
pathway activation. This process most directly reflects which
cellular function?
A. Extracellular matrix remodeling
B. Nuclear DNA transcription
C. Selective intracellular protein degradation
D. Ribosomal peptide assembly
E. Endosomal receptor recycling
8th Edition
Author(s)Sue E. Huether
TEST BANK
Q1. A 4-year-old boy presents with recurrent bacterial
infections, poor wound healing, and delayed separation of the
umbilical cord after birth. Flow cytometry demonstrates absent
β2-integrin expression on neutrophils. The patient’s recurrent
infections are most directly related to failure of which cellular
process?
A. Intracellular lysosomal degradation
B. Endothelial transcytosis of immunoglobulins
C. Leukocyte adhesion to vascular endothelium
D. Neutrophil oxidative burst generation
E. Bone marrow myeloid differentiation
,Correct Answer: C
Rationale:
Clinical Clue:
Delayed umbilical cord separation and recurrent bacterial
infections strongly suggest leukocyte adhesion deficiency.
Mechanism:
β2-integrins are required for firm leukocyte adhesion to
endothelial ICAM molecules during extravasation.
Why the Correct Answer Is Right:
Without functional integrins, neutrophils cannot migrate
effectively from blood into infected tissues despite normal
production.
Why the Other Options Are Wrong:
A. Lysosomal degradation remains intact.
B. Immunoglobulin transport is unrelated to neutrophil
migration.
D. Oxidative burst defects occur in chronic granulomatous
disease.
E. Myeloid differentiation defects cause pancytopenia rather
than adhesion failure.
Exam Trap (common misconception tested):
Confusing leukocyte migration defects with neutrophil killing
defects.
,High-Yield Clinical Correlation:
Adhesion molecule defects produce marked neutrophilia
because leukocytes remain trapped in circulation.
Q2. A researcher inhibits Na+/K+-ATPase activity in cultured
cardiac myocytes. Within minutes, cells begin swelling. The
earliest mechanism responsible for this morphologic change is
best explained by:
A. Increased intracellular oncotic pressure from protein
synthesis
B. Osmotic influx of water following intracellular sodium
accumulation
C. Mitochondrial calcium precipitation causing membrane
rupture
D. Increased lysosomal permeability with autodigestion
E. Activation of caspase-mediated apoptosis pathways
Correct Answer: B
Rationale:
Clinical Clue:
Acute inhibition of Na+/K+-ATPase causes rapid cellular
swelling.
Mechanism:
ATP-dependent sodium extrusion fails, increasing intracellular
sodium concentration and drawing water into the cell.
, Why the Correct Answer Is Right:
Loss of membrane ion gradients produces osmotic cellular
edema, an early reversible injury.
Why the Other Options Are Wrong:
A. Protein synthesis is not the immediate driver.
C. Calcium injury occurs later.
D. Lysosomal rupture characterizes severe irreversible injury.
E. Apoptosis does not initially produce swelling.
Exam Trap (common misconception tested):
Confusing reversible hydropic swelling with irreversible necrotic
injury.
High-Yield Clinical Correlation:
Cellular swelling is one of the earliest morphologic
manifestations of ATP depletion.
Q3. A woman with metastatic breast carcinoma develops
progressive cachexia despite adequate caloric intake. Biopsy of
skeletal muscle demonstrates increased ubiquitin-proteasome
pathway activation. This process most directly reflects which
cellular function?
A. Extracellular matrix remodeling
B. Nuclear DNA transcription
C. Selective intracellular protein degradation
D. Ribosomal peptide assembly
E. Endosomal receptor recycling
