NURS 6501 Advanced Pathophysiology Midterm | Walden University 2026/2027 Latest Exam
NURS 6501 Advanced Pathophysiology Midterm
Walden University • Latest 2026/2027 Exam Edition
Comprehensive 100-Question Examination with Verified A+ Answers
100 Questions • Cognitive Mix: 25% Recall / 55% Application / 20% Analysis
Format: 70% Scenario-Based • 25% Direct Recall • 5% Clinical Case Analysis
Aligned for FNP, AGNP, DNP, MSN Board Preparation (AANP/ANCC Pathophysiology Foundations)
This 100-question Walden University NURS 6501 Advanced Pathophysiology midterm examination is fully
aligned with the 2026-2027 curriculum and graduate-level advanced practice nursing competencies. The
exam covers ten integrated content domains: cellular biology and membrane function, genetics and
chromosomal disorders, immune and inflammatory mechanisms, fluid/electrolyte/acid-base balance,
endocrine pathophysiology, cardiovascular disorders, respiratory and renal pathophysiology, hematologic
disorders, neurological and musculoskeletal pathophysiology, and integrated clinical case scenarios. Each
question includes a detailed rationale explaining the cellular mechanisms, genetic principles, endocrine
physiology, hemodynamic relationships, immune hypersensitivity mechanisms, and clinical reasoning
required to select the correct answer. The exam emphasizes integrated clinical reasoning, board-relevant
distractor analysis, and the pathophysiologic basis for advanced practice nursing management.
Section 1: Cellular Biology and Membrane Function (Q1-Q15)
Q1: A 68-year-old male with chronic constipation undergoes colonoscopy, which reveals
segmental colonic dilation and loss of normal peristalsis. Biopsy shows loss of ganglion cells in
the myenteric plexus. Which cellular adaptation best describes the marked dilation of the
affected colonic segment?
A. Atrophy
B. Hypertrophy [CORRECT]
C. Compensatory hyperplasia
D. Metaplasia
Correct Answer: B
Rationale: Hypertrophy is an increase in cell SIZE (without cell division) that produces an enlarged organ or
tissue — classically seen in smooth muscle of the dilated colonic segment proximal to an obstruction (as in
Hirschsprung disease). Atrophy is a decrease in cell size (choice A); the colon wall here is enlarged, not
shrunken. Hyperplasia (choice C) is an increase in cell NUMBER and is not the dominant mechanism in
obstructive dilation of hollow organs. Metaplasia (choice D) is the reversible replacement of one differentiated
cell type by another, classically seen in Barrett esophagus or smoking-related airway changes, not in colonic
dilation.
Page 1 | NURS 6501 Midterm Exam — 100 Questions
,NURS 6501 Advanced Pathophysiology Midterm | Walden University 2026/2027 Latest Exam
Q2: A 50-year-old chronic smoker undergoes bronchoscopy. Biopsy of the bronchial epithelium
reveals replacement of the normal ciliated pseudostratified columnar epithelium with stratified
squamous epithelium. Which cellular adaptation does this finding represent, and what is its
primary biological purpose?
A. Dysplasia; precancerous irreversible change
B. Metaplasia; reversible substitution better able to withstand stress [CORRECT]
C. Anaplasia; loss of cell differentiation
D. Hyperplasia; increased cell number from hormonal stimulation
Correct Answer: B
Rationale: Metaplasia is the reversible replacement of one adult cell type by another adult cell type that is
better able to withstand chronic stress. In smokers, the normal ciliated pseudostratified columnar epithelium
of the bronchi is replaced by stratified squamous epithelium, which is more resistant to smoke toxins but loses
ciliary clearance function — increasing infection and cancer risk. Dysplasia (choice A) is disordered growth
with atypical cells (precursor to neoplasia) but is not a simple substitution of one mature cell type. Anaplasia
(choice C) is lack of differentiation seen in malignant tumors. Hyperplasia (choice D) is increased cell number
from hormones or growth factors, not cell-type substitution.
Q3: A 55-year-old male presents with a chronically obstructed urinary bladder from benign
prostatic hyperplasia. The bladder wall becomes markedly thickened. Microscopic examination
reveals increased cell number in the detrusor smooth muscle. Which adaptation is occurring, and
what is its underlying mechanism?
A. Hypertrophy only; increased cell size from mechanical stress
B. Hyperplasia; increased cell number driven by mechanical and hormonal stimulation
[CORRECT]
C. Metaplasia; urothelium converts to squamous epithelium
D. Dysplasia; disordered cellular maturation
Correct Answer: B
Rationale: Smooth muscle cells in the urinary bladder respond to chronic obstruction (mechanical stress) and
hormonal factors by undergoing both hypertrophy and hyperplasia, with hyperplasia (increased cell
NUMBER) being the dominant mechanism accounting for the thickened bladder wall. Hypertrophy alone
(choice A) describes increased cell size without division, which is more typical of cardiac and skeletal muscle
that cannot undergo hyperplasia. Metaplasia (choice C) refers to cell-type substitution (e.g., squamous
metaplasia in chronic bladder irritation), not muscle wall thickening. Dysplasia (choice D) implies disordered,
atypical growth suggestive of pre-neoplasia.
Q4: A 35-year-old female has her left kidney surgically removed after trauma. Over the next 12
months, the right kidney increases in size by 40%. Microscopic examination would most likely
demonstrate which cellular adaptation in the remaining kidney?
A. Compensatory hyperplasia [CORRECT]
B. Metaplasia of the renal tubules
C. Atrophy of the glomeruli
D. Dysplasia of the renal pelvis
Correct Answer: A
Rationale: Compensatory hyperplasia occurs in organs (such as the kidney, liver, and portions of the lung)
when remaining tissue proliferates to restore functional capacity after surgical removal or injury. The cells of
the remaining kidney increase in NUMBER, enlarging the organ. Metaplasia (choice B) is cell-type
substitution. Atrophy (choice C) is decrease in cell size. Dysplasia (choice D) is disordered pre-neoplastic
growth. Compensatory hyperplasia is hormonally regulated and differs from pathologic hyperplasia (e.g.,
endometrial hyperplasia).
Page 2 | NURS 6501 Midterm Exam — 100 Questions
,NURS 6501 Advanced Pathophysiology Midterm | Walden University 2026/2027 Latest Exam
Q5: A biopsy of cervical tissue in a 28-year-old female shows disordered cellular arrangement with
cells of varying sizes, hyperchromatic nuclei, and increased nuclear-to-cytoplasmic ratio, but the
basement membrane is intact. Which cellular adaptation is described, and what is its clinical
significance?
A. Metaplasia; benign adaptive response
B. Dysplasia; premalignant change that may progress to carcinoma in situ [CORRECT]
C. Anaplasia; malignant transformation with basement membrane invasion
D. Hyperplasia; hormonally driven proliferation
Correct Answer: B
Rationale: Dysplasia is disordered cellular proliferation characterized by loss of uniformity, pleomorphism,
hyperchromatic nuclei, and increased mitoses, but with an intact basement membrane (no invasion). It is
considered a premalignant change that may regress or progress to carcinoma in situ and invasive cancer.
Metaplasia (choice A) is substitution of one mature cell type by another. Anaplasia (choice C) implies frank
malignancy with loss of differentiation and basement membrane invasion. Hyperplasia (choice D) is increased
cell number without atypia. Cervical dysplasia (CIN) is graded by the proportion of epithelium involved.
Q6: A 70-year-old female with a long leg cast after a femur fracture develops significant wasting of
the quadriceps muscle in the immobilized leg over 6 weeks. Which cellular mechanism is most
responsible for this finding?
A. Decreased protein synthesis and increased proteolysis in muscle cells [CORRECT]
B. Loss of muscle cell number through apoptosis
C. Metaplasia of muscle to fibrous tissue
D. Sarcomere hyperplasia
Correct Answer: A
Rationale: Disuse atrophy of skeletal muscle is mediated by decreased protein synthesis, increased
ubiquitin-proteasome proteolysis, and reduced mechanical loading signals, leading to decreased cell size and
muscle wasting. Cell number (choice B) is largely preserved — atrophy is primarily a decrease in cell SIZE, not
number. Metaplasia (choice C) is cell-type substitution and does not occur in muscle. Sarcomere hyperplasia
(choice D) is the opposite of what occurs with disuse. Reversibility is possible with restored activity and
rehabilitation.
Q7: A 60-year-old male suffers a myocardial infarction. Histologic examination of the infarcted
tissue 24 hours later reveals cell swelling, ruptured plasma membranes, and an influx of
neutrophils. Which form of cell death is described, and how does it differ from apoptosis?
A. Apoptosis; energy-dependent programmed cell death with minimal inflammation
B. Necrosis; cell swelling, membrane rupture, and inflammation from ATP depletion [CORRECT]
C. Autophagy; orderly breakdown of organelles
D. Pyroptosis; caspase-1-mediated programmed necrosis
Correct Answer: B
Rationale: Necrosis is characterized by cell swelling (oncosis), membrane rupture, release of cellular
contents, and a robust inflammatory response — all consequences of ATP depletion, ionic imbalance, and
irreversible injury following ischemia. Apoptosis (choice A) is energy-dependent, programmed cell death with
nuclear fragmentation, intact membranes, and minimal inflammation. Autophagy (choice C) is a survival
mechanism involving lysosomal degradation of damaged organelles. Pyroptosis (choice D) is a specialized
inflammatory programmed cell death. The distinction is critical: necrosis is always pathologic, whereas
apoptosis can be physiologic.
Page 3 | NURS 6501 Midterm Exam — 100 Questions
, NURS 6501 Advanced Pathophysiology Midterm | Walden University 2026/2027 Latest Exam
Q8: A 45-year-old male develops acute tubular necrosis after a hypotensive episode. Cellular
injury in this scenario is initiated by depletion of which molecule, and what is the immediate
downstream consequence?
A. Depletion of ATP, leading to failure of the Na+/K+-ATPase pump and cellular swelling
[CORRECT]
B. Depletion of calcium, leading to muscle tetany
C. Depletion of glucose, leading to ketogenesis
D. Depletion of DNA, leading to mitotic catastrophe
Correct Answer: A
Rationale: Hypoxia and ischemia lead to ATP depletion, which disables the Na+/K+-ATPase pump. Sodium
accumulates intracellularly, water follows osmotically, and the cell swells (oncosis). Potassium leaks out,
calcium accumulates intracellularly (activating proteases, lipases, and endonucleases), and ultimately
membrane injury leads to cell death. The other choices misidentify the initiating molecule and consequence.
Calcium (choice B) is typically elevated (not depleted) in injured cells. Glucose depletion (choice C) is not the
primary event. DNA depletion (choice D) is not a recognized initiating event in ischemic cell injury.
Q9: A research pathologist studies the role of free radicals in cellular injury. Which of the
following mechanisms is most responsible for neutralizing hydrogen peroxide within cells, and
what co-factor is essential?
A. Superoxide dismutase; requires zinc
B. Catalase; decomposes H2O2 to water and oxygen [CORRECT]
C. Glutathione peroxidase; requires iron
D. Myeloperoxidase; requires copper
Correct Answer: B
Rationale: Catalase is the enzyme responsible for decomposing hydrogen peroxide (H2O2) into water and
oxygen, primarily in peroxisomes, thereby protecting cells from oxidative injury. Superoxide dismutase
(choice A) converts superoxide anion to H2O2, the substrate for catalase. Glutathione peroxidase (choice C)
also detoxifies H2O2 but uses selenium as a cofactor (not iron) and reduced glutathione as the electron donor.
Myeloperoxidase (choice D) generates hypochlorous acid in neutrophils. Together, these enzymes form an
antioxidant defense system against reactive oxygen species generated during ischemia-reperfusion,
inflammation, and chemical injury.
Q10: A graduate nursing student is studying ion transport. The Na+/K+-ATPase pump transports 3
Na+ out of the cell and 2 K+ into the cell for each ATP consumed. Which transport category best
describes this mechanism, and what is its direct physiologic effect on the resting membrane
potential?
A. Facilitated diffusion; no direct effect on membrane potential
B. Primary active transport; contributes to the negative resting membrane potential (electrogenic)
[CORRECT]
C. Secondary active transport; hyperpolarizes the cell
D. Simple diffusion; no ATP required
Correct Answer: B
Rationale: The Na+/K+-ATPase is a PRIMARY active transport pump because it directly uses ATP to move ions
against their electrochemical gradients (3 Na+ out, 2 K+ in). Because the pump exports more positive charge
than it imports, it is electrogenic and contributes to the negative resting membrane potential (approximately
–70 mV in neurons). Facilitated diffusion (choice A) uses a carrier but not ATP. Secondary active transport
(choice C) uses the gradient created by primary active transport (e.g., Na+-glucose symport). Simple diffusion
(choice D) requires no energy or carrier. The pump establishes the gradients necessary for secondary active
transport and action potentials.
Page 4 | NURS 6501 Midterm Exam — 100 Questions
NURS 6501 Advanced Pathophysiology Midterm
Walden University • Latest 2026/2027 Exam Edition
Comprehensive 100-Question Examination with Verified A+ Answers
100 Questions • Cognitive Mix: 25% Recall / 55% Application / 20% Analysis
Format: 70% Scenario-Based • 25% Direct Recall • 5% Clinical Case Analysis
Aligned for FNP, AGNP, DNP, MSN Board Preparation (AANP/ANCC Pathophysiology Foundations)
This 100-question Walden University NURS 6501 Advanced Pathophysiology midterm examination is fully
aligned with the 2026-2027 curriculum and graduate-level advanced practice nursing competencies. The
exam covers ten integrated content domains: cellular biology and membrane function, genetics and
chromosomal disorders, immune and inflammatory mechanisms, fluid/electrolyte/acid-base balance,
endocrine pathophysiology, cardiovascular disorders, respiratory and renal pathophysiology, hematologic
disorders, neurological and musculoskeletal pathophysiology, and integrated clinical case scenarios. Each
question includes a detailed rationale explaining the cellular mechanisms, genetic principles, endocrine
physiology, hemodynamic relationships, immune hypersensitivity mechanisms, and clinical reasoning
required to select the correct answer. The exam emphasizes integrated clinical reasoning, board-relevant
distractor analysis, and the pathophysiologic basis for advanced practice nursing management.
Section 1: Cellular Biology and Membrane Function (Q1-Q15)
Q1: A 68-year-old male with chronic constipation undergoes colonoscopy, which reveals
segmental colonic dilation and loss of normal peristalsis. Biopsy shows loss of ganglion cells in
the myenteric plexus. Which cellular adaptation best describes the marked dilation of the
affected colonic segment?
A. Atrophy
B. Hypertrophy [CORRECT]
C. Compensatory hyperplasia
D. Metaplasia
Correct Answer: B
Rationale: Hypertrophy is an increase in cell SIZE (without cell division) that produces an enlarged organ or
tissue — classically seen in smooth muscle of the dilated colonic segment proximal to an obstruction (as in
Hirschsprung disease). Atrophy is a decrease in cell size (choice A); the colon wall here is enlarged, not
shrunken. Hyperplasia (choice C) is an increase in cell NUMBER and is not the dominant mechanism in
obstructive dilation of hollow organs. Metaplasia (choice D) is the reversible replacement of one differentiated
cell type by another, classically seen in Barrett esophagus or smoking-related airway changes, not in colonic
dilation.
Page 1 | NURS 6501 Midterm Exam — 100 Questions
,NURS 6501 Advanced Pathophysiology Midterm | Walden University 2026/2027 Latest Exam
Q2: A 50-year-old chronic smoker undergoes bronchoscopy. Biopsy of the bronchial epithelium
reveals replacement of the normal ciliated pseudostratified columnar epithelium with stratified
squamous epithelium. Which cellular adaptation does this finding represent, and what is its
primary biological purpose?
A. Dysplasia; precancerous irreversible change
B. Metaplasia; reversible substitution better able to withstand stress [CORRECT]
C. Anaplasia; loss of cell differentiation
D. Hyperplasia; increased cell number from hormonal stimulation
Correct Answer: B
Rationale: Metaplasia is the reversible replacement of one adult cell type by another adult cell type that is
better able to withstand chronic stress. In smokers, the normal ciliated pseudostratified columnar epithelium
of the bronchi is replaced by stratified squamous epithelium, which is more resistant to smoke toxins but loses
ciliary clearance function — increasing infection and cancer risk. Dysplasia (choice A) is disordered growth
with atypical cells (precursor to neoplasia) but is not a simple substitution of one mature cell type. Anaplasia
(choice C) is lack of differentiation seen in malignant tumors. Hyperplasia (choice D) is increased cell number
from hormones or growth factors, not cell-type substitution.
Q3: A 55-year-old male presents with a chronically obstructed urinary bladder from benign
prostatic hyperplasia. The bladder wall becomes markedly thickened. Microscopic examination
reveals increased cell number in the detrusor smooth muscle. Which adaptation is occurring, and
what is its underlying mechanism?
A. Hypertrophy only; increased cell size from mechanical stress
B. Hyperplasia; increased cell number driven by mechanical and hormonal stimulation
[CORRECT]
C. Metaplasia; urothelium converts to squamous epithelium
D. Dysplasia; disordered cellular maturation
Correct Answer: B
Rationale: Smooth muscle cells in the urinary bladder respond to chronic obstruction (mechanical stress) and
hormonal factors by undergoing both hypertrophy and hyperplasia, with hyperplasia (increased cell
NUMBER) being the dominant mechanism accounting for the thickened bladder wall. Hypertrophy alone
(choice A) describes increased cell size without division, which is more typical of cardiac and skeletal muscle
that cannot undergo hyperplasia. Metaplasia (choice C) refers to cell-type substitution (e.g., squamous
metaplasia in chronic bladder irritation), not muscle wall thickening. Dysplasia (choice D) implies disordered,
atypical growth suggestive of pre-neoplasia.
Q4: A 35-year-old female has her left kidney surgically removed after trauma. Over the next 12
months, the right kidney increases in size by 40%. Microscopic examination would most likely
demonstrate which cellular adaptation in the remaining kidney?
A. Compensatory hyperplasia [CORRECT]
B. Metaplasia of the renal tubules
C. Atrophy of the glomeruli
D. Dysplasia of the renal pelvis
Correct Answer: A
Rationale: Compensatory hyperplasia occurs in organs (such as the kidney, liver, and portions of the lung)
when remaining tissue proliferates to restore functional capacity after surgical removal or injury. The cells of
the remaining kidney increase in NUMBER, enlarging the organ. Metaplasia (choice B) is cell-type
substitution. Atrophy (choice C) is decrease in cell size. Dysplasia (choice D) is disordered pre-neoplastic
growth. Compensatory hyperplasia is hormonally regulated and differs from pathologic hyperplasia (e.g.,
endometrial hyperplasia).
Page 2 | NURS 6501 Midterm Exam — 100 Questions
,NURS 6501 Advanced Pathophysiology Midterm | Walden University 2026/2027 Latest Exam
Q5: A biopsy of cervical tissue in a 28-year-old female shows disordered cellular arrangement with
cells of varying sizes, hyperchromatic nuclei, and increased nuclear-to-cytoplasmic ratio, but the
basement membrane is intact. Which cellular adaptation is described, and what is its clinical
significance?
A. Metaplasia; benign adaptive response
B. Dysplasia; premalignant change that may progress to carcinoma in situ [CORRECT]
C. Anaplasia; malignant transformation with basement membrane invasion
D. Hyperplasia; hormonally driven proliferation
Correct Answer: B
Rationale: Dysplasia is disordered cellular proliferation characterized by loss of uniformity, pleomorphism,
hyperchromatic nuclei, and increased mitoses, but with an intact basement membrane (no invasion). It is
considered a premalignant change that may regress or progress to carcinoma in situ and invasive cancer.
Metaplasia (choice A) is substitution of one mature cell type by another. Anaplasia (choice C) implies frank
malignancy with loss of differentiation and basement membrane invasion. Hyperplasia (choice D) is increased
cell number without atypia. Cervical dysplasia (CIN) is graded by the proportion of epithelium involved.
Q6: A 70-year-old female with a long leg cast after a femur fracture develops significant wasting of
the quadriceps muscle in the immobilized leg over 6 weeks. Which cellular mechanism is most
responsible for this finding?
A. Decreased protein synthesis and increased proteolysis in muscle cells [CORRECT]
B. Loss of muscle cell number through apoptosis
C. Metaplasia of muscle to fibrous tissue
D. Sarcomere hyperplasia
Correct Answer: A
Rationale: Disuse atrophy of skeletal muscle is mediated by decreased protein synthesis, increased
ubiquitin-proteasome proteolysis, and reduced mechanical loading signals, leading to decreased cell size and
muscle wasting. Cell number (choice B) is largely preserved — atrophy is primarily a decrease in cell SIZE, not
number. Metaplasia (choice C) is cell-type substitution and does not occur in muscle. Sarcomere hyperplasia
(choice D) is the opposite of what occurs with disuse. Reversibility is possible with restored activity and
rehabilitation.
Q7: A 60-year-old male suffers a myocardial infarction. Histologic examination of the infarcted
tissue 24 hours later reveals cell swelling, ruptured plasma membranes, and an influx of
neutrophils. Which form of cell death is described, and how does it differ from apoptosis?
A. Apoptosis; energy-dependent programmed cell death with minimal inflammation
B. Necrosis; cell swelling, membrane rupture, and inflammation from ATP depletion [CORRECT]
C. Autophagy; orderly breakdown of organelles
D. Pyroptosis; caspase-1-mediated programmed necrosis
Correct Answer: B
Rationale: Necrosis is characterized by cell swelling (oncosis), membrane rupture, release of cellular
contents, and a robust inflammatory response — all consequences of ATP depletion, ionic imbalance, and
irreversible injury following ischemia. Apoptosis (choice A) is energy-dependent, programmed cell death with
nuclear fragmentation, intact membranes, and minimal inflammation. Autophagy (choice C) is a survival
mechanism involving lysosomal degradation of damaged organelles. Pyroptosis (choice D) is a specialized
inflammatory programmed cell death. The distinction is critical: necrosis is always pathologic, whereas
apoptosis can be physiologic.
Page 3 | NURS 6501 Midterm Exam — 100 Questions
, NURS 6501 Advanced Pathophysiology Midterm | Walden University 2026/2027 Latest Exam
Q8: A 45-year-old male develops acute tubular necrosis after a hypotensive episode. Cellular
injury in this scenario is initiated by depletion of which molecule, and what is the immediate
downstream consequence?
A. Depletion of ATP, leading to failure of the Na+/K+-ATPase pump and cellular swelling
[CORRECT]
B. Depletion of calcium, leading to muscle tetany
C. Depletion of glucose, leading to ketogenesis
D. Depletion of DNA, leading to mitotic catastrophe
Correct Answer: A
Rationale: Hypoxia and ischemia lead to ATP depletion, which disables the Na+/K+-ATPase pump. Sodium
accumulates intracellularly, water follows osmotically, and the cell swells (oncosis). Potassium leaks out,
calcium accumulates intracellularly (activating proteases, lipases, and endonucleases), and ultimately
membrane injury leads to cell death. The other choices misidentify the initiating molecule and consequence.
Calcium (choice B) is typically elevated (not depleted) in injured cells. Glucose depletion (choice C) is not the
primary event. DNA depletion (choice D) is not a recognized initiating event in ischemic cell injury.
Q9: A research pathologist studies the role of free radicals in cellular injury. Which of the
following mechanisms is most responsible for neutralizing hydrogen peroxide within cells, and
what co-factor is essential?
A. Superoxide dismutase; requires zinc
B. Catalase; decomposes H2O2 to water and oxygen [CORRECT]
C. Glutathione peroxidase; requires iron
D. Myeloperoxidase; requires copper
Correct Answer: B
Rationale: Catalase is the enzyme responsible for decomposing hydrogen peroxide (H2O2) into water and
oxygen, primarily in peroxisomes, thereby protecting cells from oxidative injury. Superoxide dismutase
(choice A) converts superoxide anion to H2O2, the substrate for catalase. Glutathione peroxidase (choice C)
also detoxifies H2O2 but uses selenium as a cofactor (not iron) and reduced glutathione as the electron donor.
Myeloperoxidase (choice D) generates hypochlorous acid in neutrophils. Together, these enzymes form an
antioxidant defense system against reactive oxygen species generated during ischemia-reperfusion,
inflammation, and chemical injury.
Q10: A graduate nursing student is studying ion transport. The Na+/K+-ATPase pump transports 3
Na+ out of the cell and 2 K+ into the cell for each ATP consumed. Which transport category best
describes this mechanism, and what is its direct physiologic effect on the resting membrane
potential?
A. Facilitated diffusion; no direct effect on membrane potential
B. Primary active transport; contributes to the negative resting membrane potential (electrogenic)
[CORRECT]
C. Secondary active transport; hyperpolarizes the cell
D. Simple diffusion; no ATP required
Correct Answer: B
Rationale: The Na+/K+-ATPase is a PRIMARY active transport pump because it directly uses ATP to move ions
against their electrochemical gradients (3 Na+ out, 2 K+ in). Because the pump exports more positive charge
than it imports, it is electrogenic and contributes to the negative resting membrane potential (approximately
–70 mV in neurons). Facilitated diffusion (choice A) uses a carrier but not ATP. Secondary active transport
(choice C) uses the gradient created by primary active transport (e.g., Na+-glucose symport). Simple diffusion
(choice D) requires no energy or carrier. The pump establishes the gradients necessary for secondary active
transport and action potentials.
Page 4 | NURS 6501 Midterm Exam — 100 Questions
