Understanding Pathophysiology
8th Edition
Author(s)Sue E. Huether
TEST BANK
Q1. A 6-year-old boy presents with recurrent bacterial
infections, delayed wound healing, and poor leukocyte
migration into infected tissues. Genetic analysis reveals
defective β2-integrin expression on neutrophils. The impaired
host defense is most directly related to failure of which cellular
process?
A. Intracellular lysosomal enzyme activation
B. Cell-to-cell adhesion between leukocytes and endothelium
C. Oxidative phosphorylation within neutrophils
D. Ribosomal protein synthesis during granulopoiesis
E. Microtubule assembly during chemotaxis
,Correct Answer: B
Rationale:
Clinical Clue:
Recurrent infections with defective neutrophil migration
strongly suggest impaired leukocyte adhesion.
Mechanism:
β2-integrins mediate firm adhesion of leukocytes to endothelial
cells before transmigration into tissues.
Why the Correct Answer Is Right:
Defective integrin-mediated adhesion prevents neutrophils
from exiting circulation and entering infected tissue.
Why the Other Options Are Wrong:
A. Lysosomal dysfunction causes impaired intracellular killing,
not migration failure.
C. Oxidative phosphorylation defects would produce
generalized energy failure.
D. Ribosomal dysfunction impairs marrow production rather
than endothelial attachment.
E. Microtubule defects impair motility but do not specifically
explain adhesion failure.
Exam Trap (common misconception tested):
Confusing chemotaxis defects with adhesion molecule defects.
High-Yield Clinical Correlation:
Leukocyte adhesion deficiency produces marked neutrophilia
because neutrophils cannot leave the bloodstream.
,Q2. A researcher exposes cultured hepatocytes to cyanide.
Within minutes, ATP levels fall dramatically and sodium
accumulates intracellularly. Cellular swelling subsequently
develops. Which mechanism best accounts for the swelling?
A. Increased osmotic influx due to Na+/K+-ATPase failure
B. Excessive endocytosis of extracellular fluid
C. Enhanced mitochondrial calcium uptake
D. Activation of membrane phospholipases
E. Accelerated protein synthesis within the rough endoplasmic
reticulum
Correct Answer: A
Rationale:
Clinical Clue:
Rapid ATP depletion followed by intracellular sodium
accumulation indicates membrane pump failure.
Mechanism:
ATP depletion disables Na+/K+-ATPase activity, causing
intracellular sodium and water retention.
Why the Correct Answer Is Right:
Loss of active sodium extrusion creates osmotic water influx
and cellular swelling.
Why the Other Options Are Wrong:
B. Endocytosis is not the primary driver of acute swelling.
, C. Mitochondrial calcium uptake contributes to injury but not
immediate swelling.
D. Phospholipase activation causes membrane damage later in
injury progression.
E. Protein synthesis decreases during ATP depletion.
Exam Trap (common misconception tested):
Assuming membrane rupture is the earliest event in hypoxic
injury.
High-Yield Clinical Correlation:
Cellular swelling is one of the earliest reversible manifestations
of ATP depletion.
Q3. A patient with metastatic lung carcinoma develops severe
hypercalcemia. Cells exposed to persistently elevated
intracellular calcium are at greatest risk for activation of which
process?
A. DNA methylation
B. Cytoskeletal protein degradation
C. Increased glycogen synthesis
D. Enhanced membrane receptor recycling
E. Suppression of mitochondrial permeability transition
Correct Answer: B
Rationale:
8th Edition
Author(s)Sue E. Huether
TEST BANK
Q1. A 6-year-old boy presents with recurrent bacterial
infections, delayed wound healing, and poor leukocyte
migration into infected tissues. Genetic analysis reveals
defective β2-integrin expression on neutrophils. The impaired
host defense is most directly related to failure of which cellular
process?
A. Intracellular lysosomal enzyme activation
B. Cell-to-cell adhesion between leukocytes and endothelium
C. Oxidative phosphorylation within neutrophils
D. Ribosomal protein synthesis during granulopoiesis
E. Microtubule assembly during chemotaxis
,Correct Answer: B
Rationale:
Clinical Clue:
Recurrent infections with defective neutrophil migration
strongly suggest impaired leukocyte adhesion.
Mechanism:
β2-integrins mediate firm adhesion of leukocytes to endothelial
cells before transmigration into tissues.
Why the Correct Answer Is Right:
Defective integrin-mediated adhesion prevents neutrophils
from exiting circulation and entering infected tissue.
Why the Other Options Are Wrong:
A. Lysosomal dysfunction causes impaired intracellular killing,
not migration failure.
C. Oxidative phosphorylation defects would produce
generalized energy failure.
D. Ribosomal dysfunction impairs marrow production rather
than endothelial attachment.
E. Microtubule defects impair motility but do not specifically
explain adhesion failure.
Exam Trap (common misconception tested):
Confusing chemotaxis defects with adhesion molecule defects.
High-Yield Clinical Correlation:
Leukocyte adhesion deficiency produces marked neutrophilia
because neutrophils cannot leave the bloodstream.
,Q2. A researcher exposes cultured hepatocytes to cyanide.
Within minutes, ATP levels fall dramatically and sodium
accumulates intracellularly. Cellular swelling subsequently
develops. Which mechanism best accounts for the swelling?
A. Increased osmotic influx due to Na+/K+-ATPase failure
B. Excessive endocytosis of extracellular fluid
C. Enhanced mitochondrial calcium uptake
D. Activation of membrane phospholipases
E. Accelerated protein synthesis within the rough endoplasmic
reticulum
Correct Answer: A
Rationale:
Clinical Clue:
Rapid ATP depletion followed by intracellular sodium
accumulation indicates membrane pump failure.
Mechanism:
ATP depletion disables Na+/K+-ATPase activity, causing
intracellular sodium and water retention.
Why the Correct Answer Is Right:
Loss of active sodium extrusion creates osmotic water influx
and cellular swelling.
Why the Other Options Are Wrong:
B. Endocytosis is not the primary driver of acute swelling.
, C. Mitochondrial calcium uptake contributes to injury but not
immediate swelling.
D. Phospholipase activation causes membrane damage later in
injury progression.
E. Protein synthesis decreases during ATP depletion.
Exam Trap (common misconception tested):
Assuming membrane rupture is the earliest event in hypoxic
injury.
High-Yield Clinical Correlation:
Cellular swelling is one of the earliest reversible manifestations
of ATP depletion.
Q3. A patient with metastatic lung carcinoma develops severe
hypercalcemia. Cells exposed to persistently elevated
intracellular calcium are at greatest risk for activation of which
process?
A. DNA methylation
B. Cytoskeletal protein degradation
C. Increased glycogen synthesis
D. Enhanced membrane receptor recycling
E. Suppression of mitochondrial permeability transition
Correct Answer: B
Rationale:
