NU606 | NU606 Advanced Pathophysiology Exam 1
Version 3 Questions with Correct Answers and
Expert Explanation for Each Question
1. A patient exhibits a decrease in muscle size after being in a cast for six weeks. This
cellular adaptation is best described as:
A. Hypertrophy
B. Dysplasia
C. Metaplasia
D. Atrophy
Correct Answer: D
Expert Explanation: Atrophy is a decrease in cellular size caused by aging, disuse,
or reduced blood supply. This reduction in size often leads to a decrease in the
functional capacity of the affected organ. In this clinical scenario, the lack of
mechanical use of the muscle resulted in disuse atrophy.
2. Which cellular process involves the programmed cell death of damaged or
unnecessary cells without an inflammatory response?
A. Necrosis
B. Autophagy
C. Apoptosis
,D. Oncosis
Correct Answer: C
Expert Explanation: Apoptosis is an active process of cellular self-destruction that
is genetically programmed. Unlike necrosis, apoptosis does not cause an
inflammatory response because the cell components are cleared by phagocytes. This
process is essential for normal development and the removal of potentially harmful
cells.
3. The movement of water between the intracellular and extracellular compartments
is primarily determined by:
A. Hydrostatic pressure
B. Active transport
C. Pinocytosis
D. Osmotic pressure
Correct Answer: D
Expert Explanation: Osmotic pressure is the force that pulls water toward an area
of higher solute concentration. Since water moves freely across cell membranes, its
distribution is dictated by the concentration of electrolytes, particularly sodium in
the ECF and potassium in the ICF. This balance ensures that the volumes of the
compartments remain relatively stable.
,4. A patient has a pH of 7.25, a PaCO2 of 55 mmHg, and a HCO3 of 24 mEq/L. What is
the acid-base imbalance?
A. Metabolic acidosis
B. Metabolic alkalosis
C. Respiratory acidosis
D. Respiratory alkalosis
Correct Answer: C
Expert Explanation: The pH of 7.25 indicates acidosis since it is below the normal
range of 7.35 to 7.45. The elevated PaCO2 of 55 mmHg suggests that the acidosis is
caused by the retention of carbon dioxide in the lungs. Because the bicarbonate level
is within the normal range, this is identified as uncompensated respiratory acidosis.
5. Which of the following describes the mechanism of cellular injury caused by free
radicals?
A. Excessive production of ATP within the mitochondria
B. Creation of oxidative stress leading to membrane damage
C. Increased DNA repair through methylation
D. Reduction of intracellular calcium levels
Correct Answer: B
, Expert Explanation: Free radicals are highly reactive atoms with unpaired
electrons that can damage lipids, proteins, and DNA. Oxidative stress occurs when
the production of these reactive oxygen species exceeds the body’s antioxidant
defenses. This leads to the destruction of cellular membranes and often results in
cell death.
6. A child is diagnosed with Down syndrome. Which chromosomal abnormality is
typically responsible for this condition?
A. Monosomy X
B. XXY Genotype
C. Trisomy 18
D. Trisomy 21
Correct Answer: D
Expert Explanation: Down syndrome is most commonly caused by trisomy 21,
where an individual has three copies of chromosome 21 instead of two. This usually
results from nondisjunction during meiosis, leading to an extra chromosome in the
gamete. The presence of this extra genetic material alters the course of development
and causes the characteristic features of the syndrome.
Version 3 Questions with Correct Answers and
Expert Explanation for Each Question
1. A patient exhibits a decrease in muscle size after being in a cast for six weeks. This
cellular adaptation is best described as:
A. Hypertrophy
B. Dysplasia
C. Metaplasia
D. Atrophy
Correct Answer: D
Expert Explanation: Atrophy is a decrease in cellular size caused by aging, disuse,
or reduced blood supply. This reduction in size often leads to a decrease in the
functional capacity of the affected organ. In this clinical scenario, the lack of
mechanical use of the muscle resulted in disuse atrophy.
2. Which cellular process involves the programmed cell death of damaged or
unnecessary cells without an inflammatory response?
A. Necrosis
B. Autophagy
C. Apoptosis
,D. Oncosis
Correct Answer: C
Expert Explanation: Apoptosis is an active process of cellular self-destruction that
is genetically programmed. Unlike necrosis, apoptosis does not cause an
inflammatory response because the cell components are cleared by phagocytes. This
process is essential for normal development and the removal of potentially harmful
cells.
3. The movement of water between the intracellular and extracellular compartments
is primarily determined by:
A. Hydrostatic pressure
B. Active transport
C. Pinocytosis
D. Osmotic pressure
Correct Answer: D
Expert Explanation: Osmotic pressure is the force that pulls water toward an area
of higher solute concentration. Since water moves freely across cell membranes, its
distribution is dictated by the concentration of electrolytes, particularly sodium in
the ECF and potassium in the ICF. This balance ensures that the volumes of the
compartments remain relatively stable.
,4. A patient has a pH of 7.25, a PaCO2 of 55 mmHg, and a HCO3 of 24 mEq/L. What is
the acid-base imbalance?
A. Metabolic acidosis
B. Metabolic alkalosis
C. Respiratory acidosis
D. Respiratory alkalosis
Correct Answer: C
Expert Explanation: The pH of 7.25 indicates acidosis since it is below the normal
range of 7.35 to 7.45. The elevated PaCO2 of 55 mmHg suggests that the acidosis is
caused by the retention of carbon dioxide in the lungs. Because the bicarbonate level
is within the normal range, this is identified as uncompensated respiratory acidosis.
5. Which of the following describes the mechanism of cellular injury caused by free
radicals?
A. Excessive production of ATP within the mitochondria
B. Creation of oxidative stress leading to membrane damage
C. Increased DNA repair through methylation
D. Reduction of intracellular calcium levels
Correct Answer: B
, Expert Explanation: Free radicals are highly reactive atoms with unpaired
electrons that can damage lipids, proteins, and DNA. Oxidative stress occurs when
the production of these reactive oxygen species exceeds the body’s antioxidant
defenses. This leads to the destruction of cellular membranes and often results in
cell death.
6. A child is diagnosed with Down syndrome. Which chromosomal abnormality is
typically responsible for this condition?
A. Monosomy X
B. XXY Genotype
C. Trisomy 18
D. Trisomy 21
Correct Answer: D
Expert Explanation: Down syndrome is most commonly caused by trisomy 21,
where an individual has three copies of chromosome 21 instead of two. This usually
results from nondisjunction during meiosis, leading to an extra chromosome in the
gamete. The presence of this extra genetic material alters the course of development
and causes the characteristic features of the syndrome.
