NURS 6501 Midterm & Final Exam – 250
Questions with Answers & Explanations |
Latest 2026 Advanced Pathophysiology
Walden Study Guide
SECTION 1: CELLULAR BIOLOGY AND MEMBRANE FUNCTION (Questions 1–40)
1. A runner has depleted all available oxygen for muscle energy. Which of the
following will facilitate continued muscle performance?
A. Aerobic respiration
B. Creatine phosphate accumulation
C. Anaerobic glycolysis
D. Beta-oxidation of fatty acids
Answer: C. Anaerobic glycolysis allows muscle cells to produce ATP without oxygen by
breaking down glucose to pyruvate and then lactate. This process yields only 2 ATP per
glucose versus 36 to 38 ATP with aerobic metabolism, but it provides rapid energy when
oxygen is depleted .
2. What causes the rapid change in the resting membrane potential that initiates an
action potential?
A. Potassium gates open and potassium rushes out of the cell
,B. Sodium gates open and sodium rushes into the cell
C. Calcium gates open and calcium rushes into the cell
D. Chloride gates open and chloride enters the cell
Answer: B. Depolarization occurs when voltage-gated sodium channels open in response to
threshold stimulation, allowing sodium ions to flow down their electrochemical gradient into
the cell. This rapid sodium influx shifts the membrane potential from approximately −70 mV
toward a positive value of +30 mV .
3. A patient has a genetic defect that causes the sodium-potassium pump to function
at only 20 percent efficiency. What expected finding does the healthcare professional
relate to this defect?
A. Increased intracellular sodium concentration
B. Decreased intracellular sodium concentration
C. Increased intracellular potassium concentration
D. Normal intracellular sodium concentration
Answer: A. The sodium-potassium ATPase pump actively transports sodium out of the cell
and potassium into the cell. If the pump functions at reduced efficiency, sodium
accumulates inside the cell. This disrupts the electrochemical gradient essential for nerve
impulse transmission and osmotic balance .
4. How are potassium and sodium transported across plasma membranes?
A. By simple diffusion
B. By facilitated diffusion through ion channels
C. By adenosine triphosphate enzyme ATPase activity
D. By osmosis
,Answer: C. The Na⁺/K⁺ ATPase pump actively transports 3 sodium ions out of the cell and
2 potassium ions into the cell against their concentration gradients. This requires ATP
energy and maintains the electrochemical gradient essential for cellular function .
5. The ion transporter that moves sodium and calcium simultaneously in the same
direction is an example of which type of transport?
A. Antiport
B. Symport
C. Uniport
D. Primary active transport
Answer: B. Symport is a type of coupled transport where two or more different molecules or
ions are transported in the same direction across a membrane .
6. A cell exposed to prolonged sublethal hypoxia accumulates misfolded proteins in
the ER lumen. Which adaptive response most directly restores proteostasis and
prevents apoptosis in this setting?
A. Activation of the unfolded protein response (UPR) with upregulation of chaperones and
ERAD
B. Induction of autophagy via mTORC1 activation
C. Increased mitochondrial biogenesis through PGC-1 suppression
D. Shift to anaerobic glycolysis with lactate dehydrogenase inhibition
Answer: A. The UPR senses ER stress and increases chaperones and ER-associated
degradation (ERAD) to restore folding capacity. mTORC1 activation inhibits autophagy,
PGC-1 suppression reduces mitochondrial function, and LDH inhibition would worsen
anaerobic ATP production .
, 7. Which cellular adaptation is characterized by an increase in the size of existing
cells?
A. Hyperplasia
B. Dysplasia
C. Hypertrophy
D. Metaplasia
Answer: C. Hypertrophy occurs when cells increase in size, resulting in enlargement of the
affected tissue or organ. Cardiac muscle enlargement in hypertension is a common
example .
8. Apoptosis is best described as:
A. Cell swelling due to injury
B. Programmed cell death
C. Tissue necrosis from ischemia
D. Irreversible mitochondrial damage
Answer: B. Apoptosis is a regulated process that eliminates damaged or unnecessary cells
without provoking significant inflammation .
9. Which of the following is a hallmark of reversible cell injury?
A. Karyolysis
B. Cell membrane rupture
C. Cellular swelling
D. Mitochondrial calcification
Answer: C. Reversible cell injury often involves cellular swelling due to failure of ion pumps
in the plasma membrane .
Questions with Answers & Explanations |
Latest 2026 Advanced Pathophysiology
Walden Study Guide
SECTION 1: CELLULAR BIOLOGY AND MEMBRANE FUNCTION (Questions 1–40)
1. A runner has depleted all available oxygen for muscle energy. Which of the
following will facilitate continued muscle performance?
A. Aerobic respiration
B. Creatine phosphate accumulation
C. Anaerobic glycolysis
D. Beta-oxidation of fatty acids
Answer: C. Anaerobic glycolysis allows muscle cells to produce ATP without oxygen by
breaking down glucose to pyruvate and then lactate. This process yields only 2 ATP per
glucose versus 36 to 38 ATP with aerobic metabolism, but it provides rapid energy when
oxygen is depleted .
2. What causes the rapid change in the resting membrane potential that initiates an
action potential?
A. Potassium gates open and potassium rushes out of the cell
,B. Sodium gates open and sodium rushes into the cell
C. Calcium gates open and calcium rushes into the cell
D. Chloride gates open and chloride enters the cell
Answer: B. Depolarization occurs when voltage-gated sodium channels open in response to
threshold stimulation, allowing sodium ions to flow down their electrochemical gradient into
the cell. This rapid sodium influx shifts the membrane potential from approximately −70 mV
toward a positive value of +30 mV .
3. A patient has a genetic defect that causes the sodium-potassium pump to function
at only 20 percent efficiency. What expected finding does the healthcare professional
relate to this defect?
A. Increased intracellular sodium concentration
B. Decreased intracellular sodium concentration
C. Increased intracellular potassium concentration
D. Normal intracellular sodium concentration
Answer: A. The sodium-potassium ATPase pump actively transports sodium out of the cell
and potassium into the cell. If the pump functions at reduced efficiency, sodium
accumulates inside the cell. This disrupts the electrochemical gradient essential for nerve
impulse transmission and osmotic balance .
4. How are potassium and sodium transported across plasma membranes?
A. By simple diffusion
B. By facilitated diffusion through ion channels
C. By adenosine triphosphate enzyme ATPase activity
D. By osmosis
,Answer: C. The Na⁺/K⁺ ATPase pump actively transports 3 sodium ions out of the cell and
2 potassium ions into the cell against their concentration gradients. This requires ATP
energy and maintains the electrochemical gradient essential for cellular function .
5. The ion transporter that moves sodium and calcium simultaneously in the same
direction is an example of which type of transport?
A. Antiport
B. Symport
C. Uniport
D. Primary active transport
Answer: B. Symport is a type of coupled transport where two or more different molecules or
ions are transported in the same direction across a membrane .
6. A cell exposed to prolonged sublethal hypoxia accumulates misfolded proteins in
the ER lumen. Which adaptive response most directly restores proteostasis and
prevents apoptosis in this setting?
A. Activation of the unfolded protein response (UPR) with upregulation of chaperones and
ERAD
B. Induction of autophagy via mTORC1 activation
C. Increased mitochondrial biogenesis through PGC-1 suppression
D. Shift to anaerobic glycolysis with lactate dehydrogenase inhibition
Answer: A. The UPR senses ER stress and increases chaperones and ER-associated
degradation (ERAD) to restore folding capacity. mTORC1 activation inhibits autophagy,
PGC-1 suppression reduces mitochondrial function, and LDH inhibition would worsen
anaerobic ATP production .
, 7. Which cellular adaptation is characterized by an increase in the size of existing
cells?
A. Hyperplasia
B. Dysplasia
C. Hypertrophy
D. Metaplasia
Answer: C. Hypertrophy occurs when cells increase in size, resulting in enlargement of the
affected tissue or organ. Cardiac muscle enlargement in hypertension is a common
example .
8. Apoptosis is best described as:
A. Cell swelling due to injury
B. Programmed cell death
C. Tissue necrosis from ischemia
D. Irreversible mitochondrial damage
Answer: B. Apoptosis is a regulated process that eliminates damaged or unnecessary cells
without provoking significant inflammation .
9. Which of the following is a hallmark of reversible cell injury?
A. Karyolysis
B. Cell membrane rupture
C. Cellular swelling
D. Mitochondrial calcification
Answer: C. Reversible cell injury often involves cellular swelling due to failure of ion pumps
in the plasma membrane .
