McCance & Huether’s Pathophysiology
The Biologic Basis for Disease in Adults and Children
9th Edition
• Author(s)Julia Rogers
TEST BANK
1
Reference
Ch. 1 — Prokaryotes and Eukaryotes
Stem
A hospitalized patient’s blood culture grows a small organism
that lacks a true nucleus and has 70S ribosomes on microscopic
analysis. The patient develops fever and increasing neutrophil
count. Which cellular characteristic most strongly supports
classifying this organism as prokaryotic and guides antibiotic
selection?
A. Presence of a double-membrane nuclear envelope
B. Circular chromosome without histones
C. Membrane-bound organelles such as mitochondria
D. Linear chromosomes packaged with histones
Correct answer: B
Rationale
Correct (B): Prokaryotes characteristically have a single, circular
,chromosome and lack histones; McCance emphasizes these
structural differences that explain unique
transcription/translation targets for antibiotics (e.g., 70S
ribosomes). Identifying a circular, histone-free chromosome
supports prokaryotic identity and helps the clinician select
drugs targeting prokaryotic ribosomes. This is the safest
interpretation for treatment choice.
Incorrect (A): A nuclear envelope indicates a eukaryote;
prokaryotes lack a nucleus. Not consistent with the organism
described.
Incorrect (C): Presence of membrane-bound organelles is a
eukaryotic feature; the organism lacks these.
Incorrect (D): Linear chromosomes with histones are
eukaryotic; this contradicts the 70S ribosome finding and would
mislead therapy selection.
Teaching point: Prokaryotes: circular chromosome, no histones,
70S ribosomes — key antibiotic targets.
Citation: Rogers, J., et al. (2023). Pathophysiology: The Biologic
Basis for Disease in Adults and Children (9th ed.). Ch. 1.
2
Reference
Ch. 1 — Cellular Functions
Stem
A 68-year-old with chronic heart failure has progressive
,dyspnea and elevated lactate after hypotension. At the bedside,
there is cool skin and delayed capillary refill. Which cellular
function failure best explains the systemic lactic acidosis and
organ hypoperfusion?
A. Impaired cellular replication
B. Loss of aerobic respiration (oxidative phosphorylation)
C. Excessive cellular secretion of cytokines
D. Increased cell-to-cell adhesion
Correct answer: B
Rationale
Correct (B): McCance explains that when oxygen delivery falls,
oxidative phosphorylation fails and cells shift to anaerobic
glycolysis producing lactate. In hypoperfusion from heart
failure, mitochondrial aerobic respiration is impaired, causing
systemic lactic acidosis and end-organ hypoxia—an immediate
safety concern.
Incorrect (A): Impaired replication affects tissue repair over
time but does not acutely produce lactic acidosis.
Incorrect (C): Cytokine secretion contributes to inflammation
and vasodilation but does not directly cause cellular shift to
anaerobic metabolism as the primary mechanism here.
Incorrect (D): Increased adhesion would affect tissue integrity,
not global energy metabolism or lactate production.
Teaching point: In hypoperfusion, mitochondrial oxidative
phosphorylation fails → anaerobic glycolysis → lactic acidosis.
, Citation: Rogers, J., et al. (2023). Pathophysiology: The Biologic
Basis for Disease in Adults and Children (9th ed.). Ch. 1.
3
Reference
Ch. 1 — Structure and Function of Cellular Components
Stem
A 45-year-old presents after an overdose of a toxin that
uncouples oxidative phosphorylation. His arterial lactate is high
and oxygen consumption is increased despite hypotension.
Which organelle dysfunction best explains the increased oxygen
use with diminished ATP production?
A. Lysosomal membrane rupture
B. Mitochondrial inner membrane proton leak
C. Rough endoplasmic reticulum stress
D. Golgi apparatus trafficking failure
Correct answer: B
Rationale
Correct (B): McCance describes uncoupling agents that increase
proton permeability of the mitochondrial inner membrane,
dissipating the proton motive force. This causes increased
oxygen consumption without ATP synthesis (proton leak),
explaining high oxygen use and low ATP generation—critical to
recognize clinically.
Incorrect (A): Lysosomal rupture causes intracellular digestion
The Biologic Basis for Disease in Adults and Children
9th Edition
• Author(s)Julia Rogers
TEST BANK
1
Reference
Ch. 1 — Prokaryotes and Eukaryotes
Stem
A hospitalized patient’s blood culture grows a small organism
that lacks a true nucleus and has 70S ribosomes on microscopic
analysis. The patient develops fever and increasing neutrophil
count. Which cellular characteristic most strongly supports
classifying this organism as prokaryotic and guides antibiotic
selection?
A. Presence of a double-membrane nuclear envelope
B. Circular chromosome without histones
C. Membrane-bound organelles such as mitochondria
D. Linear chromosomes packaged with histones
Correct answer: B
Rationale
Correct (B): Prokaryotes characteristically have a single, circular
,chromosome and lack histones; McCance emphasizes these
structural differences that explain unique
transcription/translation targets for antibiotics (e.g., 70S
ribosomes). Identifying a circular, histone-free chromosome
supports prokaryotic identity and helps the clinician select
drugs targeting prokaryotic ribosomes. This is the safest
interpretation for treatment choice.
Incorrect (A): A nuclear envelope indicates a eukaryote;
prokaryotes lack a nucleus. Not consistent with the organism
described.
Incorrect (C): Presence of membrane-bound organelles is a
eukaryotic feature; the organism lacks these.
Incorrect (D): Linear chromosomes with histones are
eukaryotic; this contradicts the 70S ribosome finding and would
mislead therapy selection.
Teaching point: Prokaryotes: circular chromosome, no histones,
70S ribosomes — key antibiotic targets.
Citation: Rogers, J., et al. (2023). Pathophysiology: The Biologic
Basis for Disease in Adults and Children (9th ed.). Ch. 1.
2
Reference
Ch. 1 — Cellular Functions
Stem
A 68-year-old with chronic heart failure has progressive
,dyspnea and elevated lactate after hypotension. At the bedside,
there is cool skin and delayed capillary refill. Which cellular
function failure best explains the systemic lactic acidosis and
organ hypoperfusion?
A. Impaired cellular replication
B. Loss of aerobic respiration (oxidative phosphorylation)
C. Excessive cellular secretion of cytokines
D. Increased cell-to-cell adhesion
Correct answer: B
Rationale
Correct (B): McCance explains that when oxygen delivery falls,
oxidative phosphorylation fails and cells shift to anaerobic
glycolysis producing lactate. In hypoperfusion from heart
failure, mitochondrial aerobic respiration is impaired, causing
systemic lactic acidosis and end-organ hypoxia—an immediate
safety concern.
Incorrect (A): Impaired replication affects tissue repair over
time but does not acutely produce lactic acidosis.
Incorrect (C): Cytokine secretion contributes to inflammation
and vasodilation but does not directly cause cellular shift to
anaerobic metabolism as the primary mechanism here.
Incorrect (D): Increased adhesion would affect tissue integrity,
not global energy metabolism or lactate production.
Teaching point: In hypoperfusion, mitochondrial oxidative
phosphorylation fails → anaerobic glycolysis → lactic acidosis.
, Citation: Rogers, J., et al. (2023). Pathophysiology: The Biologic
Basis for Disease in Adults and Children (9th ed.). Ch. 1.
3
Reference
Ch. 1 — Structure and Function of Cellular Components
Stem
A 45-year-old presents after an overdose of a toxin that
uncouples oxidative phosphorylation. His arterial lactate is high
and oxygen consumption is increased despite hypotension.
Which organelle dysfunction best explains the increased oxygen
use with diminished ATP production?
A. Lysosomal membrane rupture
B. Mitochondrial inner membrane proton leak
C. Rough endoplasmic reticulum stress
D. Golgi apparatus trafficking failure
Correct answer: B
Rationale
Correct (B): McCance describes uncoupling agents that increase
proton permeability of the mitochondrial inner membrane,
dissipating the proton motive force. This causes increased
oxygen consumption without ATP synthesis (proton leak),
explaining high oxygen use and low ATP generation—critical to
recognize clinically.
Incorrect (A): Lysosomal rupture causes intracellular digestion
