NR 507 – Advanced Pathophysiology: Weeks 1–4 Midterm Exam Questions and Correct Answers

NR 507 – Advanced Pathophysiology: Weeks 1–4 Midterm Exam
Questions and Correct Answers



QUESTION 1:
Which cellular component is primarily responsible for generating ATP through oxidative
phosphorylation?
A. Ribosome
B. Mitochondrion
C. Golgi apparatus
D. Endoplasmic reticulum

CORRECT ANSWER: B. Mitochondrion
RATIONALE: Mitochondria are the “powerhouses” of the cell, converting nutrients into ATP. The
electron transport chain within mitochondrial membranes drives oxidative phosphorylation.



QUESTION 2:
Which process best describes cellular adaptation to chronic low oxygen levels?
A. Hyperplasia
B. Hypertrophy
C. Atrophy
D. Metaplasia

CORRECT ANSWER: B. Hypertrophy
RATIONALE: Under chronic hypoxia, cells—especially muscle cells—adapt by enlarging to
improve efficiency and oxygen use, which defines hypertrophy.



QUESTION 3:
Apoptosis differs from necrosis primarily because:
A. It occurs only in cancerous tissue
B. It involves uncontrolled cell swelling
C. It is a programmed and non-inflammatory process
D. It is always caused by infection

,CORRECT ANSWER: C. It is a programmed and non-inflammatory process
RATIONALE: Apoptosis is a regulated, energy-dependent form of cell death that prevents
inflammation, unlike necrosis, which involves membrane rupture and inflammation.



QUESTION 4:
Which electrolyte imbalance is most commonly associated with metabolic acidosis?
A. Hypokalemia
B. Hyperkalemia
C. Hypocalcemia
D. Hypernatremia

CORRECT ANSWER: B. Hyperkalemia
RATIONALE: In acidosis, hydrogen ions move into cells as potassium exits, increasing serum
potassium concentration.



QUESTION 5:
True or False: Free radicals primarily cause cell injury by lipid peroxidation of membranes.

CORRECT ANSWER: True
RATIONALE: Reactive oxygen species attack membrane lipids, leading to structural damage,
increased permeability, and cellular dysfunction.



QUESTION 6:
In an inflammatory response, histamine release primarily causes:
A. Vasoconstriction
B. Increased vascular permeability
C. Reduced leukocyte migration
D. Clot formation

CORRECT ANSWER: B. Increased vascular permeability
RATIONALE: Histamine dilates arterioles and increases permeability, facilitating leukocyte and
plasma escape to injured tissues.



QUESTION 7:
A genetic mutation resulting in substitution of a single base pair is termed:

,A. Frameshift mutation
B. Deletion
C. Point mutation
D. Transversion

CORRECT ANSWER: C. Point mutation
RATIONALE: A point mutation alters a single nucleotide base, potentially changing an amino acid
sequence or causing no change at all (silent mutation).



QUESTION 8:
During the stress response, which hormone increases glucose availability from the liver?
A. Aldosterone
B. Cortisol
C. Insulin
D. Estrogen

CORRECT ANSWER: B. Cortisol
RATIONALE: Cortisol promotes gluconeogenesis and glycogenolysis, ensuring adequate
metabolic fuel during physiological stress.



QUESTION 9:
Which immune cells are responsible for the presentation of antigens to helper T cells?
A. Basophils
B. Neutrophils
C. Macrophages and dendritic cells
D. Natural killer cells

CORRECT ANSWER: C. Macrophages and dendritic cells
RATIONALE: These antigen-presenting cells internalize pathogens, process them, and display
antigen fragments via MHC II molecules to T-helper cells.



QUESTION 10:
In Type I hypersensitivity reactions, which immunoglobulin mediates the response?
A. IgA
B. IgE

, C. IgM
D. IgG

CORRECT ANSWER: B. IgE
RATIONALE: IgE binds to mast cells, triggering histamine release upon antigen exposure and
leading to allergic responses.



QUESTION 11:
The principal mechanism of edema in congestive heart failure is:
A. Increased capillary permeability
B. Decreased plasma oncotic pressure
C. Increased hydrostatic pressure
D. Lymphatic obstruction

CORRECT ANSWER: C. Increased hydrostatic pressure
RATIONALE: Backing of venous blood elevates hydrostatic pressure, causing fluid transudation
into interstitial spaces.



QUESTION 12:
In respiratory acidosis, the compensatory mechanism involves:
A. Decreased renal bicarbonate reabsorption
B. Increased renal hydrogen ion secretion
C. Reduction of respiratory rate
D. Decreased aldosterone secretion

CORRECT ANSWER: B. Increased renal hydrogen ion secretion
RATIONALE: Kidneys compensate by excreting more hydrogen and retaining bicarbonate to
restore acid-base balance.



QUESTION 13:
Which condition is caused by a deficiency of phenylalanine hydroxylase?
A. Tay–Sachs disease
B. Phenylketonuria (PKU)
C. Cystic fibrosis
D. Sickle cell disease