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 bacterial
infections and poor wound healing. Flow cytometry
, demonstrates defective expression of integrins on
neutrophils, resulting in impaired adhesion to vascular
endothelium. The failure of leukocyte migration is most
directly related to disruption of which cellular structure?
A. Tight junctions
B. Gap junctions
C. Desmosomes
D. Cell adhesion molecules
E. Caveolae
Correct Answer: D
Rationale:
• Clinical Clue: Recurrent infections with defective leukocyte
adhesion strongly suggests impaired cellular adhesion
signaling.
• Mechanism: Cell adhesion molecules (CAMs), including
integrins and selectins, mediate leukocyte rolling,
adhesion, and transmigration through endothelium.
• Why the Correct Answer Is Right: Integrins are CAMs that
anchor leukocytes to endothelial surfaces during
inflammation.
• Why the Other Options Are Wrong:
o A. Tight junctions regulate paracellular permeability.
o B. Gap junctions allow ion exchange between
adjacent cells.
, o C. Desmosomes provide mechanical stability between
epithelial cells.
o E. Caveolae participate in endocytosis and signal
organization.
• Exam Trap: Confusing structural junctions with dynamic
adhesion molecules involved in immune trafficking.
• High-Yield Clinical Correlation: Leukocyte adhesion
deficiency results from defective integrin-mediated
adhesion.
• Memory Anchor: “Integrins let immune cells integrate into
tissues.”
Q2. A researcher exposes cultured hepatocytes to cyanide,
causing abrupt cessation of oxidative phosphorylation.
Within minutes, intracellular ATP levels decline sharply.
Which membrane transport process will fail first as a direct
consequence?
A. Facilitated diffusion of glucose
B. Osmosis through aquaporins
C. Sodium-potassium ATPase activity
D. Passive diffusion of oxygen
E. Chloride movement through ion channels
Correct Answer: C
Rationale:
, • Clinical Clue: ATP depletion from cyanide poisoning
primarily impairs energy-dependent transport.
• Mechanism: The sodium-potassium ATPase requires ATP
to maintain electrochemical gradients across the plasma
membrane.
• Why the Correct Answer Is Right: Active transport
mechanisms are immediately compromised during ATP
depletion.
• Why the Other Options Are Wrong:
o A. Facilitated diffusion does not directly require ATP.
o B. Osmosis is passive.
o D. Oxygen diffusion occurs down a concentration
gradient.
o E. Passive ion channel movement does not directly
consume ATP.
• Exam Trap: Assuming all membrane transport mechanisms
require energy.
• High-Yield Clinical Correlation: Failure of Na+/K+ pumps
leads to cellular swelling and eventual membrane rupture.
• Memory Anchor: “ATP loss collapses ion gradients first.”
Q3. A patient with chronic alcohol use develops
hepatocellular injury associated with excessive reactive
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 bacterial
infections and poor wound healing. Flow cytometry
, demonstrates defective expression of integrins on
neutrophils, resulting in impaired adhesion to vascular
endothelium. The failure of leukocyte migration is most
directly related to disruption of which cellular structure?
A. Tight junctions
B. Gap junctions
C. Desmosomes
D. Cell adhesion molecules
E. Caveolae
Correct Answer: D
Rationale:
• Clinical Clue: Recurrent infections with defective leukocyte
adhesion strongly suggests impaired cellular adhesion
signaling.
• Mechanism: Cell adhesion molecules (CAMs), including
integrins and selectins, mediate leukocyte rolling,
adhesion, and transmigration through endothelium.
• Why the Correct Answer Is Right: Integrins are CAMs that
anchor leukocytes to endothelial surfaces during
inflammation.
• Why the Other Options Are Wrong:
o A. Tight junctions regulate paracellular permeability.
o B. Gap junctions allow ion exchange between
adjacent cells.
, o C. Desmosomes provide mechanical stability between
epithelial cells.
o E. Caveolae participate in endocytosis and signal
organization.
• Exam Trap: Confusing structural junctions with dynamic
adhesion molecules involved in immune trafficking.
• High-Yield Clinical Correlation: Leukocyte adhesion
deficiency results from defective integrin-mediated
adhesion.
• Memory Anchor: “Integrins let immune cells integrate into
tissues.”
Q2. A researcher exposes cultured hepatocytes to cyanide,
causing abrupt cessation of oxidative phosphorylation.
Within minutes, intracellular ATP levels decline sharply.
Which membrane transport process will fail first as a direct
consequence?
A. Facilitated diffusion of glucose
B. Osmosis through aquaporins
C. Sodium-potassium ATPase activity
D. Passive diffusion of oxygen
E. Chloride movement through ion channels
Correct Answer: C
Rationale:
, • Clinical Clue: ATP depletion from cyanide poisoning
primarily impairs energy-dependent transport.
• Mechanism: The sodium-potassium ATPase requires ATP
to maintain electrochemical gradients across the plasma
membrane.
• Why the Correct Answer Is Right: Active transport
mechanisms are immediately compromised during ATP
depletion.
• Why the Other Options Are Wrong:
o A. Facilitated diffusion does not directly require ATP.
o B. Osmosis is passive.
o D. Oxygen diffusion occurs down a concentration
gradient.
o E. Passive ion channel movement does not directly
consume ATP.
• Exam Trap: Assuming all membrane transport mechanisms
require energy.
• High-Yield Clinical Correlation: Failure of Na+/K+ pumps
leads to cellular swelling and eventual membrane rupture.
• Memory Anchor: “ATP loss collapses ion gradients first.”
Q3. A patient with chronic alcohol use develops
hepatocellular injury associated with excessive reactive
