NR 412 Exam 1: Pathophysiology V4 Updated and Latest
Questions and Correct Answers - Regis University
1. Which term describes a decrease in the size of cells resulting in a reduced tissue mass?
A. Hypertrophy
B. Hyperplasia
C. Atrophy
D. Metaplasia
Correct Answer: C
Explanation: Atrophy is characterized by a reduction in cell size through the loss of substance. This
cellular adaptation often occurs due to decreased workload, loss of innervation, or diminished blood
supply. Hypertrophy involves an increase in cell size rather than a decrease. Hyperplasia refers to an
increase in the total number of cells in a tissue. Metaplasia is the reversible replacement of one mature
cell type by another less mature cell type. In clinical practice, atrophy is commonly seen in skeletal
muscles of patients who are bedridden for long periods. The process involves decreased protein
synthesis and increased protein degradation within the cell. This adaptation allows the cell to survive in
environments with limited resources. Medical professionals must identify the underlying cause of
atrophy to prevent permanent tissue loss. Proper nutrition and physical therapy can sometimes reverse
certain types of physiological atrophy.
2. What is the primary mechanism of cellular injury caused by hypoxia?
A. Increased ATP production
B. Cellular dehydration
C. Decreased intracellular calcium
D. Reduced sodium-potassium pump activity
Correct Answer: D
Explanation: Hypoxia leads to a failure of oxidative phosphorylation, which severely depletes ATP levels
within the cell. Without sufficient ATP, the sodium-potassium membrane pump fails to function correctly.
Increased ATP production is impossible under hypoxic conditions because oxygen is lacking for the
electron transport chain. Decreased intracellular calcium is incorrect because ATP failure actually leads
to an influx of calcium into the cytoplasm. Cellular dehydration does not occur; instead, the cell swells
due to an influx of water following sodium. This swelling is known as oncosis or vacuolar degeneration.
The failure of the pump causes sodium to accumulate inside the cell, creating an osmotic gradient. If
oxygen is not restored, the damage to the mitochondria and membranes becomes irreversible. This
process is a hallmark of ischemic injury in cardiac and neural tissues. Understanding this mechanism
helps clinicians manage reperfusion strategies effectively.
,3. Which type of cell death involves a programmed sequence of events and does not
typically cause inflammation?
A. Necrosis
B. Autophagy
C. Apoptosis
D. Gangrene
Correct Answer: C
Explanation: Apoptosis is a distinct type of programmed cell death used to eliminate unwanted or
damaged cells. It is characterized by the shrinking of the cell and fragmentation of the nucleus into neat
bodies. Necrosis is a messy process that results in membrane rupture and the release of inflammatory
contents. Autophagy is a survival mechanism where the cell eats its own components but is not primarily
a death category here. Gangrene is a clinical term for large areas of necrotic tissue usually caused by
ischemia and infection. In apoptosis, the cellular fragments are quickly removed by phagocytes without
eliciting an immune response. This process is vital for normal embryonic development and the regulation
of the immune system. It can be triggered by either intrinsic mitochondrial pathways or extrinsic death
receptor pathways. Dysregulation of apoptosis is linked to the development of various cancers and
autoimmune diseases. Monitoring apoptotic markers helps in assessing the efficacy of chemotherapy
treatments.
4. A patient presents with swelling in the lower extremities. Which force is most likely
responsible for this edema?
A. Lymphatic drainage enhancement
B. Increased plasma oncotic pressure
C. Decreased capillary permeability
D. Increased capillary hydrostatic pressure
Correct Answer: D
Explanation: Increased capillary hydrostatic pressure pushes fluid out of the vascular space and into the
interstitial tissues. This is a common cause of edema in conditions like heart failure or venous
obstruction. Increased plasma oncotic pressure would actually pull fluid back into the vessels, reducing
edema. Decreased capillary permeability would limit the movement of fluid and proteins, preventing
swelling. Lymphatic drainage enhancement would help clear interstitial fluid and decrease the
appearance of edema. Edema can also be caused by a decrease in plasma proteins like albumin, which
lowers oncotic pressure. Clinical assessment of edema involves checking for pitting and measuring the
circumference of the affected limb. Chronic edema can lead to skin breakdown and increased risk of
localized infections. Management often involves the use of diuretics and compression stockings to shift
fluid balance. Understanding the Starling forces is essential for diagnosing the root cause of fluid
accumulation.
, 5. Which hormone is primarily responsible for the retention of water by the kidneys?
A. Aldosterone
B. Atrial natriuretic peptide
C. Renin
D. Antidiuretic hormone
Correct Answer: D
Explanation: Antidiuretic hormone, or ADH, acts on the distal tubules of the kidney to increase water
reabsorption. It is released by the posterior pituitary gland in response to high plasma osmolality.
Aldosterone primarily promotes sodium retention, which indirectly leads to water retention. Atrial
natriuretic peptide is released by the heart to promote sodium and water excretion. Renin is an enzyme
that initiates the pathway leading to the production of angiotensin and aldosterone. ADH works by
inserting aquaporins into the collecting duct membranes to facilitate water movement. In the absence of
ADH, the kidneys produce a large volume of dilute urine. Conditions like Diabetes Insipidus involve a lack
of or resistance to ADH activity. Conversely, SIADH results in excessive water retention and dangerous
hyponatremia. Balancing ADH levels is critical for maintaining stable blood pressure and electrolyte
concentrations.
6. A blood gas report shows pH 7.30, PaCO2 50 mmHg, and HCO3 24 mEq/L. What is the
interpretation?
A. Metabolic Acidosis
B. Respiratory Alkalosis
C. Metabolic Alkalosis
D. Respiratory Acidosis
Correct Answer: D
Explanation: The pH of 7.30 indicates acidosis because it is below the normal range of 7.35 to 7.45. The
PaCO2 is elevated at 50 mmHg, which suggests a respiratory cause for the acidic pH. Metabolic acidosis
would typically show a low bicarbonate level, which is not present here. Respiratory alkalosis would
require a high pH and a low PaCO2 value. Metabolic alkalosis involves a high pH and a high bicarbonate
level. The bicarbonate level of 24 is within the normal range, indicating no compensation has occurred
yet. This state is common in patients with hypoventilation or chronic obstructive pulmonary disease. The
primary goal in treating respiratory acidosis is to improve ventilation and gas exchange. If the condition
persists, the kidneys will eventually begin to retain bicarbonate to compensate. Monitoring arterial blood
gases is vital for managing patients on mechanical ventilation.
Questions and Correct Answers - Regis University
1. Which term describes a decrease in the size of cells resulting in a reduced tissue mass?
A. Hypertrophy
B. Hyperplasia
C. Atrophy
D. Metaplasia
Correct Answer: C
Explanation: Atrophy is characterized by a reduction in cell size through the loss of substance. This
cellular adaptation often occurs due to decreased workload, loss of innervation, or diminished blood
supply. Hypertrophy involves an increase in cell size rather than a decrease. Hyperplasia refers to an
increase in the total number of cells in a tissue. Metaplasia is the reversible replacement of one mature
cell type by another less mature cell type. In clinical practice, atrophy is commonly seen in skeletal
muscles of patients who are bedridden for long periods. The process involves decreased protein
synthesis and increased protein degradation within the cell. This adaptation allows the cell to survive in
environments with limited resources. Medical professionals must identify the underlying cause of
atrophy to prevent permanent tissue loss. Proper nutrition and physical therapy can sometimes reverse
certain types of physiological atrophy.
2. What is the primary mechanism of cellular injury caused by hypoxia?
A. Increased ATP production
B. Cellular dehydration
C. Decreased intracellular calcium
D. Reduced sodium-potassium pump activity
Correct Answer: D
Explanation: Hypoxia leads to a failure of oxidative phosphorylation, which severely depletes ATP levels
within the cell. Without sufficient ATP, the sodium-potassium membrane pump fails to function correctly.
Increased ATP production is impossible under hypoxic conditions because oxygen is lacking for the
electron transport chain. Decreased intracellular calcium is incorrect because ATP failure actually leads
to an influx of calcium into the cytoplasm. Cellular dehydration does not occur; instead, the cell swells
due to an influx of water following sodium. This swelling is known as oncosis or vacuolar degeneration.
The failure of the pump causes sodium to accumulate inside the cell, creating an osmotic gradient. If
oxygen is not restored, the damage to the mitochondria and membranes becomes irreversible. This
process is a hallmark of ischemic injury in cardiac and neural tissues. Understanding this mechanism
helps clinicians manage reperfusion strategies effectively.
,3. Which type of cell death involves a programmed sequence of events and does not
typically cause inflammation?
A. Necrosis
B. Autophagy
C. Apoptosis
D. Gangrene
Correct Answer: C
Explanation: Apoptosis is a distinct type of programmed cell death used to eliminate unwanted or
damaged cells. It is characterized by the shrinking of the cell and fragmentation of the nucleus into neat
bodies. Necrosis is a messy process that results in membrane rupture and the release of inflammatory
contents. Autophagy is a survival mechanism where the cell eats its own components but is not primarily
a death category here. Gangrene is a clinical term for large areas of necrotic tissue usually caused by
ischemia and infection. In apoptosis, the cellular fragments are quickly removed by phagocytes without
eliciting an immune response. This process is vital for normal embryonic development and the regulation
of the immune system. It can be triggered by either intrinsic mitochondrial pathways or extrinsic death
receptor pathways. Dysregulation of apoptosis is linked to the development of various cancers and
autoimmune diseases. Monitoring apoptotic markers helps in assessing the efficacy of chemotherapy
treatments.
4. A patient presents with swelling in the lower extremities. Which force is most likely
responsible for this edema?
A. Lymphatic drainage enhancement
B. Increased plasma oncotic pressure
C. Decreased capillary permeability
D. Increased capillary hydrostatic pressure
Correct Answer: D
Explanation: Increased capillary hydrostatic pressure pushes fluid out of the vascular space and into the
interstitial tissues. This is a common cause of edema in conditions like heart failure or venous
obstruction. Increased plasma oncotic pressure would actually pull fluid back into the vessels, reducing
edema. Decreased capillary permeability would limit the movement of fluid and proteins, preventing
swelling. Lymphatic drainage enhancement would help clear interstitial fluid and decrease the
appearance of edema. Edema can also be caused by a decrease in plasma proteins like albumin, which
lowers oncotic pressure. Clinical assessment of edema involves checking for pitting and measuring the
circumference of the affected limb. Chronic edema can lead to skin breakdown and increased risk of
localized infections. Management often involves the use of diuretics and compression stockings to shift
fluid balance. Understanding the Starling forces is essential for diagnosing the root cause of fluid
accumulation.
, 5. Which hormone is primarily responsible for the retention of water by the kidneys?
A. Aldosterone
B. Atrial natriuretic peptide
C. Renin
D. Antidiuretic hormone
Correct Answer: D
Explanation: Antidiuretic hormone, or ADH, acts on the distal tubules of the kidney to increase water
reabsorption. It is released by the posterior pituitary gland in response to high plasma osmolality.
Aldosterone primarily promotes sodium retention, which indirectly leads to water retention. Atrial
natriuretic peptide is released by the heart to promote sodium and water excretion. Renin is an enzyme
that initiates the pathway leading to the production of angiotensin and aldosterone. ADH works by
inserting aquaporins into the collecting duct membranes to facilitate water movement. In the absence of
ADH, the kidneys produce a large volume of dilute urine. Conditions like Diabetes Insipidus involve a lack
of or resistance to ADH activity. Conversely, SIADH results in excessive water retention and dangerous
hyponatremia. Balancing ADH levels is critical for maintaining stable blood pressure and electrolyte
concentrations.
6. A blood gas report shows pH 7.30, PaCO2 50 mmHg, and HCO3 24 mEq/L. What is the
interpretation?
A. Metabolic Acidosis
B. Respiratory Alkalosis
C. Metabolic Alkalosis
D. Respiratory Acidosis
Correct Answer: D
Explanation: The pH of 7.30 indicates acidosis because it is below the normal range of 7.35 to 7.45. The
PaCO2 is elevated at 50 mmHg, which suggests a respiratory cause for the acidic pH. Metabolic acidosis
would typically show a low bicarbonate level, which is not present here. Respiratory alkalosis would
require a high pH and a low PaCO2 value. Metabolic alkalosis involves a high pH and a high bicarbonate
level. The bicarbonate level of 24 is within the normal range, indicating no compensation has occurred
yet. This state is common in patients with hypoventilation or chronic obstructive pulmonary disease. The
primary goal in treating respiratory acidosis is to improve ventilation and gas exchange. If the condition
persists, the kidneys will eventually begin to retain bicarbonate to compensate. Monitoring arterial blood
gases is vital for managing patients on mechanical ventilation.
