PATHOPHYSIOLOGY FINAL EXAM: 3
VERSIONS
VERSION 1: QUESTIONS 1-67
SECTION A: CELLULAR PATHOPHYSIOLOGY & GENETICS (Questions
1-15)
Question 1
A patient experiences prolonged hypoxia following a myocardial infarction. Which
intracellular process is the primary cause of cellular swelling?
A. Increased lysosomal membrane stability
B. Failure of ATP-dependent sodium-potassium pumps
C. Increased protein synthesis
D. Activation of apoptosis
Answer: B
Rationale: Hypoxia leads to decreased ATP production, impairing the Na⁺/K⁺-
ATPase pump function. This causes intracellular sodium accumulation, drawing
water into the cell and resulting in cellular swelling. This is the earliest
morphologic sign of reversible injury. Lysosomal membrane stability decreases,
not increases, during hypoxia. Apoptosis is an energy-dependent process that
occurs later, if at all .
Question 2
Which mechanism best explains reperfusion injury following ischemia?
A. Restoration of normal mitochondrial ATP production
B. Decreased neutrophil activation
,C. Generation of reactive oxygen species and inflammatory mediators
D. Suppression of cytokine release
Answer: C
Rationale: Reperfusion introduces oxygen that generates reactive oxygen species
(free radicals) and triggers an inflammatory response, which paradoxically worsens
tissue damage rather than reversing it. The generation of ROS causes oxidative
damage to cell membranes, proteins, and DNA. Neutrophil activation increases,
not decreases, during reperfusion .
Question 3
Which cell component is capable of cellular autodigestion when released during
cell injury?
A. Lysosomes
B. Ribosomes
C. Smooth endoplasmic reticulum
D. Golgi complex
Answer: A
Rationale: Lysosomes contain hydrolytic enzymes (hydrolases) capable of
digesting cellular components. When lysosomal membranes rupture during cell
injury, these enzymes are released into the cytoplasm, initiating autodigestion and
necrosis. Ribosomes are involved in protein synthesis, the smooth ER in lipid
metabolism, and the Golgi in protein modification .
Question 4
Which component of the cell produces hydrogen peroxide (H₂O₂) by using oxygen
to remove hydrogen atoms from specific substrates?
A. Lysosomes
B. Peroxisomes
C. Ribosomes
D. Oxysomes
,Answer: B
Rationale: Peroxisomes contain oxidative enzymes that use oxygen to remove
hydrogen atoms from substrates in oxidative reactions, producing hydrogen
peroxide (H₂O₂). They also contain catalase, which breaks down H₂O₂ to water and
oxygen. Lysosomes contain hydrolytic enzymes, ribosomes synthesize proteins,
and oxysomes are not cellular organelles .
Question 5
Which characteristic distinguishes apoptosis from necrosis?
A. Apoptosis causes inflammation
B. Apoptosis involves programmed cell death of scattered single cells
C. Apoptosis involves unpredictable patterns of cell death
D. Apoptosis results in cell swelling
Answer: B
Rationale: Apoptosis is a tightly regulated, energy-dependent process of
programmed cell death affecting scattered single cells without triggering
inflammation. Cell contents are packaged into apoptotic bodies that are
phagocytosed by macrophages. Necrosis, in contrast, causes cell swelling,
membrane rupture, release of cellular contents, and triggers inflammation .
Question 6
What is a consequence of plasma membrane damage to the mitochondria?
A. Increased ATP production
B. Release of cytochrome c and initiation of apoptosis
C. Enhanced protein synthesis
D. Increased calcium efflux
Answer: B
Rationale: Plasma membrane damage can lead to mitochondrial injury, resulting
in the release of cytochrome c from the mitochondrial intermembrane space.
Cytochrome c activates caspases, triggering the intrinsic apoptotic pathway. This
, leads to mitochondrial membrane permeability transition and ultimately cell death.
K. K. K. K. K. K. K. K. K.
ATP production decreases, and calcium enters the cell, further damaging
K. K. K. K. K. K. K. K. K. K.
mitochondria .
K. K.
Question 7 K.
During cell injury caused by hypoxia, sodium and water move into the cell
K. K. K. K. K. K. K. K. K. K. K. K.
because:
K.
A. The sodium-potassium pump cannot function due to decreased ATP
K. K. K. K. K. K. K. K.
B. Oxygen is not available to bind with sodium to maintain it outside the cell
K. K. K. K. K. K. K. K. K. K. K. K. K.
C. The osmotic pressure is increased, pulling additional sodium across the
K. K. K. K. K. K. K. K. K.
membrane
K.
D. The cell membrane becomes impermeable to sodium
K. K. K. K. K. K.
Answer: A K.
Rationale: The Na⁺/K⁺-ATPase pump requires ATP to actively transport sodium
K. K. K. K. K. K. K. K. K.
out of the cell and potassium into the cell. During hypoxia, ATP production
K. K. K. K. K. K. K. K. K. K. K. K. K.
decreases, leading to pump failure. Sodium accumulates intracellularly, creating an
K. K. K. K. K. K. K. K. K. K.
osmotic gradient that draws water into the cell, causing cellular swelling .
K. K. K. K. K. K. K. K. K. K. K. K.
Question 8 K.
Which organ is most sensitive to hypoxia?
K. K. K. K. K. K.
A. Liver
B. Kidney
C. Brain
D. Skeletal muscle K.
Answer: C K.
Rationale: Brain tissue is exquisitely sensitive to hypoxia because neurons have
K. K. K. K. K. K. K. K. K. K.
high metabolic demands and limited anaerobic capacity. Irreversible injury occurs
K. K. K. K. K. K. K. K. K. K.
within 3-5 minutes of complete oxygen deprivation. The liver and kidneys can
K. K. K. K. K. K. K. K. K. K. K. K.
tolerate longer periods of hypoxia, and skeletal muscle is relatively resistant .
K. K. K. K. K. K. K. K. K. K. K. K.