Question 1
A 67-year-old patient experiences an acute myocardial infarction caused by complete
occlusion of the left anterior descending coronary artery. During the early stages of ischemia,
myocardial cells develop swelling and reduced contractility.
,Which cellular mechanism most directly explains the initial swelling?
A. Increased ATP production stimulates sodium influx.
B. Failure of the sodium-potassium ATPase causes intracellular sodium and water
accumulation.
C. Increased mitochondrial oxidative phosphorylation causes osmotic changes.
D. Activation of caspases produces immediate apoptotic cell shrinkage.
Correct Answer: B. Failure of the sodium-potassium ATPase causes intracellular sodium and
water accumulation.
Rationale:
Myocardial ischemia decreases oxygen delivery and impairs mitochondrial oxidative
phosphorylation. ATP production declines, reducing the activity of ATP-dependent
membrane pumps.
Failure of the sodium-potassium ATPase allows sodium to accumulate intracellularly. Water
follows sodium through osmotic movement, producing cellular swelling.
This is an early manifestation of potentially reversible cellular injury. Prolonged ischemia
causes membrane damage, calcium overload, and irreversible cell death.
Why the Other Options Are Incorrect:
A. ATP production decreases rather than increases during ischemia.
B. This is the correct mechanism because pump failure produces sodium and water
accumulation.
C. Oxidative phosphorylation is impaired by oxygen deprivation.
D. Apoptosis involves regulated cellular dismantling and is not the primary explanation for
early ischemic swelling.
Question 2
A 59-year-old patient with longstanding hypertension develops concentric left ventricular
hypertrophy.
Which pathophysiological adaptation best explains this finding?
A. Hyperplasia resulting from increased cardiomyocyte division.
B. Metaplasia resulting from replacement of cardiac muscle with epithelial tissue.
C. Atrophy resulting from reduced myocardial workload.
,D. Hypertrophy resulting from increased cardiomyocyte size in response to pressure
overload.
Correct Answer: D. Hypertrophy resulting from increased cardiomyocyte size in response to
pressure overload.
Rationale:
Chronic systemic hypertension increases left ventricular afterload. Cardiomyocytes respond
by increasing contractile protein synthesis and cellular size.
Because mature cardiomyocytes have limited proliferative capacity, pressure overload
primarily produces hypertrophy rather than hyperplasia.
Concentric hypertrophy initially helps normalize ventricular wall stress but can eventually
cause reduced ventricular compliance, impaired relaxation, and heart failure with preserved
ejection fraction.
Why the Other Options Are Incorrect:
A. Hyperplasia refers to an increase in cell number and is not the predominant adaptation in
adult myocardium.
B. Metaplasia involves replacement of one differentiated cell type by another.
C. Atrophy occurs when cellular size decreases, commonly because of reduced workload or
nutrient availability.
D. This correctly describes the myocardial response to chronic pressure overload.
Question 3
A patient develops severe ischemic injury involving the myocardium. Histological
examination demonstrates preserved tissue architecture with eosinophilic cells lacking nuclei.
Which type of necrosis is most consistent with these findings?
A. Coagulative necrosis.
B. Liquefactive necrosis.
C. Caseous necrosis.
D. Fat necrosis.
Correct Answer: A. Coagulative necrosis.
Rationale:
, Coagulative necrosis is characteristic of ischemic infarction in most solid organs, including
the heart and kidneys.
Protein denaturation preserves the general tissue architecture temporarily, even though the
cells are no longer viable.
Microscopic findings include increased cytoplasmic eosinophilia and loss of nuclear detail.
Why the Other Options Are Incorrect:
A. This is correct because ischemic myocardial infarction typically produces coagulative
necrosis.
B. Liquefactive necrosis is characteristic of cerebral infarction and many abscesses.
C. Caseous necrosis is classically associated with tuberculosis.
D. Fat necrosis is associated with conditions such as acute pancreatitis and traumatic injury to
adipose tissue.
Question 4
A patient with a severe bacterial infection develops fever, leukocytosis, and increased C-
reactive protein.
Which mediator is most directly responsible for stimulating hepatic production of acute-
phase proteins such as C-reactive protein?
A. Histamine.
B. Immunoglobulin E.
C. Interleukin-6.
D. Acetylcholine.
Correct Answer: C. Interleukin-6.
Rationale:
Interleukin-6 is a major cytokine involved in the systemic acute-phase response.
During infection and inflammation, activated immune cells release inflammatory mediators,
including IL-6, IL-1, and tumor necrosis factor.
IL-6 stimulates hepatocytes to synthesize acute-phase proteins, including C-reactive protein
and fibrinogen.
CRP is a nonspecific marker of inflammation and does not independently identify the
causative pathogen.
A 67-year-old patient experiences an acute myocardial infarction caused by complete
occlusion of the left anterior descending coronary artery. During the early stages of ischemia,
myocardial cells develop swelling and reduced contractility.
,Which cellular mechanism most directly explains the initial swelling?
A. Increased ATP production stimulates sodium influx.
B. Failure of the sodium-potassium ATPase causes intracellular sodium and water
accumulation.
C. Increased mitochondrial oxidative phosphorylation causes osmotic changes.
D. Activation of caspases produces immediate apoptotic cell shrinkage.
Correct Answer: B. Failure of the sodium-potassium ATPase causes intracellular sodium and
water accumulation.
Rationale:
Myocardial ischemia decreases oxygen delivery and impairs mitochondrial oxidative
phosphorylation. ATP production declines, reducing the activity of ATP-dependent
membrane pumps.
Failure of the sodium-potassium ATPase allows sodium to accumulate intracellularly. Water
follows sodium through osmotic movement, producing cellular swelling.
This is an early manifestation of potentially reversible cellular injury. Prolonged ischemia
causes membrane damage, calcium overload, and irreversible cell death.
Why the Other Options Are Incorrect:
A. ATP production decreases rather than increases during ischemia.
B. This is the correct mechanism because pump failure produces sodium and water
accumulation.
C. Oxidative phosphorylation is impaired by oxygen deprivation.
D. Apoptosis involves regulated cellular dismantling and is not the primary explanation for
early ischemic swelling.
Question 2
A 59-year-old patient with longstanding hypertension develops concentric left ventricular
hypertrophy.
Which pathophysiological adaptation best explains this finding?
A. Hyperplasia resulting from increased cardiomyocyte division.
B. Metaplasia resulting from replacement of cardiac muscle with epithelial tissue.
C. Atrophy resulting from reduced myocardial workload.
,D. Hypertrophy resulting from increased cardiomyocyte size in response to pressure
overload.
Correct Answer: D. Hypertrophy resulting from increased cardiomyocyte size in response to
pressure overload.
Rationale:
Chronic systemic hypertension increases left ventricular afterload. Cardiomyocytes respond
by increasing contractile protein synthesis and cellular size.
Because mature cardiomyocytes have limited proliferative capacity, pressure overload
primarily produces hypertrophy rather than hyperplasia.
Concentric hypertrophy initially helps normalize ventricular wall stress but can eventually
cause reduced ventricular compliance, impaired relaxation, and heart failure with preserved
ejection fraction.
Why the Other Options Are Incorrect:
A. Hyperplasia refers to an increase in cell number and is not the predominant adaptation in
adult myocardium.
B. Metaplasia involves replacement of one differentiated cell type by another.
C. Atrophy occurs when cellular size decreases, commonly because of reduced workload or
nutrient availability.
D. This correctly describes the myocardial response to chronic pressure overload.
Question 3
A patient develops severe ischemic injury involving the myocardium. Histological
examination demonstrates preserved tissue architecture with eosinophilic cells lacking nuclei.
Which type of necrosis is most consistent with these findings?
A. Coagulative necrosis.
B. Liquefactive necrosis.
C. Caseous necrosis.
D. Fat necrosis.
Correct Answer: A. Coagulative necrosis.
Rationale:
, Coagulative necrosis is characteristic of ischemic infarction in most solid organs, including
the heart and kidneys.
Protein denaturation preserves the general tissue architecture temporarily, even though the
cells are no longer viable.
Microscopic findings include increased cytoplasmic eosinophilia and loss of nuclear detail.
Why the Other Options Are Incorrect:
A. This is correct because ischemic myocardial infarction typically produces coagulative
necrosis.
B. Liquefactive necrosis is characteristic of cerebral infarction and many abscesses.
C. Caseous necrosis is classically associated with tuberculosis.
D. Fat necrosis is associated with conditions such as acute pancreatitis and traumatic injury to
adipose tissue.
Question 4
A patient with a severe bacterial infection develops fever, leukocytosis, and increased C-
reactive protein.
Which mediator is most directly responsible for stimulating hepatic production of acute-
phase proteins such as C-reactive protein?
A. Histamine.
B. Immunoglobulin E.
C. Interleukin-6.
D. Acetylcholine.
Correct Answer: C. Interleukin-6.
Rationale:
Interleukin-6 is a major cytokine involved in the systemic acute-phase response.
During infection and inflammation, activated immune cells release inflammatory mediators,
including IL-6, IL-1, and tumor necrosis factor.
IL-6 stimulates hepatocytes to synthesize acute-phase proteins, including C-reactive protein
and fibrinogen.
CRP is a nonspecific marker of inflammation and does not independently identify the
causative pathogen.
