Exam 1 - NR283 / NR 283 (Latest
): Pathophysiology -
Chamberlain
Question 1 — Cellular Injury
Which of the following cellular changes is most indicative of reversible cell injury?
A. Nuclear fragmentation
B. Cellular swelling
C. Plasma membrane rupture
D. Lysosomal rupture
Correct Answer: B. Cellular swelling
Explanation:
Cellular swelling is an early, reversible indicator of cell injury due to impaired ion pumps and
water influx. Nuclear fragmentation and membrane rupture reflect irreversible injury leading to
cell death. Lysosomal rupture releases degradative enzymes and indicates advanced
degeneration.
Question 2 — Inflammation
During acute inflammation, which of the following mediators causes vasodilation and increased
vascular permeability?
A. Interferon
B. Histamine
C. Insulin
D. Dopamine
Correct Answer: B. Histamine
Explanation:
Histamine, released from mast cells and basophils, is a key mediator in acute inflammation that
causes arteriolar vasodilation and increased capillary permeability, allowing plasma proteins and
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leukocytes to exit vessels into injured tissue. Interferon is an antiviral cytokine; insulin and
dopamine are not primary inflammatory mediators.
Question 3 — Immunity
Which immunoglobulin is most important in defending against mucosal pathogens and is highly
abundant in secretions such as saliva and breast milk?
A. IgA
B. IgG
C. IgM
D. IgE
Correct Answer: A. IgA
Explanation:
IgA is the primary immunoglobulin in mucosal secretions and provides frontline defense at
respiratory and gastrointestinal surfaces. IgG is most abundant in serum and crosses the placenta;
IgM is the first antibody produced in a new immune response; IgE is involved in allergic
responses.
Question 4 — Genetic Mutations
A point mutation resulting in substitution of one amino acid for another in a protein is known as:
A. Frameshift mutation
B. Nonsense mutation
C. Missense mutation
D. Deletion
Correct Answer: C. Missense mutation
Explanation:
A missense mutation changes a single nucleotide, resulting in a different amino acid. A nonsense
mutation creates a premature stop codon. Frameshift mutations (insertions/deletions) alter the
reading frame, dramatically changing protein structure. A deletion removes nucleotides but may
or may not cause a frameshift.
Question 5 — Cell Adaptation
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Which type of cell adaptation describes an increase in cell size due to increased workload?
A. Hyperplasia
B. Metaplasia
C. Hypertrophy
D. Dysplasia
Correct Answer: C. Hypertrophy
Explanation:
Hypertrophy is an increase in cell size (e.g., skeletal muscle growth with exercise, left ventricular
hypertrophy with hypertension). Hyperplasia is an increase in cell number; metaplasia is
conversion of one cell type to another; dysplasia is disordered growth often preceding cancer.
Question 6 — Acid-Base Balance
A patient with diabetic ketoacidosis presents with low pH and low bicarbonate on arterial blood
gas. What acid-base disturbance is most likely?
A. Metabolic alkalosis
B. Metabolic acidosis
C. Respiratory acidosis
D. Respiratory alkalosis
Correct Answer: B. Metabolic acidosis
Explanation:
Diabetic ketoacidosis leads to accumulation of ketoacids, lowering blood pH and bicarbonate.
This primary metabolic acidosis can produce Kussmaul respirations as the respiratory system
compensates by blowing off CO₂.
Question 7 — Fluid & Electrolytes
A hospitalized patient with dehydration will most likely show which laboratory finding?
A. Decreased hematocrit
B. Increased hematocrit
C. Decreased serum sodium
D. Increased urine output
Correct Answer: B. Increased hematocrit
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Explanation:
Dehydration concentrates blood components, often increasing hematocrit and blood urea
nitrogen. Serum sodium may be high with water loss or low depending on electrolyte losses;
urine output often decreases without adequate intake.
Question 8 — Tissue Integrity
Which of the following wound healing phases is characterized by collagen deposition and
angiogenesis?
A. Inflammatory phase
B. Proliferative phase
C. Maturation (remodeling) phase
D. Coagulation phase
Correct Answer: B. Proliferative phase
Explanation:
The proliferative phase of wound healing involves fibroblast proliferation, collagen synthesis,
angiogenesis, and granulation tissue formation. The inflammatory phase clears debris; the
maturation phase strengthens collagen and remodels the scar.
Question 9 — Neoplasia
A benign tumor is best described as:
A. Rapidly growing and metastatic
B. Poorly differentiated and invasive
C. Slow-growing and encapsulated
D. Originating from lymphocytes
Correct Answer: C. Slow-growing and encapsulated
Explanation:
Benign tumors are typically slow-growing, well-differentiated, and often encapsulated,
remaining localized without invading or metastasizing. Malignant tumors tend to be poorly
differentiated, invasive, and capable of metastasis.
Question 10 — Cellular Communication