WGU D115 OA Advanced
Pathophysiology Exam (Latest 2026)
Actual Questions with Detailed
Answers and OA Readiness Practice
Exam
1. A patient with systemic lupus erythematosus (SLE) presents
with facial rash across the cheeks and nose, as well as proteinuria
on urinalysis. Which pathophysiologic mechanism best explains
this presentation?
A) Type I IgE-mediated hypersensitivity to environmental
triggers
B) Autoantibody formation leading to immune complex
deposition in tissues
C) T-cell-mediated destruction of melanocytes in the skin
D) Complement deficiency resulting in recurrent bacterial
infections
Answer: B. SLE is a systemic autoimmune disease characterized
by autoantibody formation (e.g., anti-nuclear antibodies). Immune
complexes deposit in small vessels of skin, kidneys, joints, and
serosal surfaces, leading to the classic malar rash and
glomerulonephritis (proteinuria). Type I hypersensitivity is
associated with allergic conditions (e.g., anaphylaxis), not SLE.
,2. A 30-year-old woman presents with fluctuating muscle
weakness, particularly ptosis and diplopia that worsen with
repeated eye movements but improve after rest. Acetylcholine
receptor antibodies are detected. Which cellular mechanism
underlies this condition?
A) Presynaptic calcium channel blockade preventing
neurotransmitter release
B) Postsynaptic nicotinic acetylcholine receptor destruction
by autoantibodies
C) Impaired axonal conduction velocity due to demyelination
D) Genetic defect in dystrophin protein leading to muscle
fiber necrosis
Answer: B. The presentation describes myasthenia gravis, an
autoimmune disorder in which autoantibodies target and destroy
postsynaptic nicotinic ACh receptors at the neuromuscular
junction. This reduces available receptors, causing fatigable
weakness that improves with rest. Option A describes Lambert-
Eaton syndrome, option C describes multiple sclerosis, and option
D describes Duchenne muscular dystrophy.
3. A 25-year-old man is evaluated for infertility. Physical exam
reveals small, firm testes and gynecomastia. Karyotype analysis
shows 47,XXY. Which pathophysiologic consequence most directly
explains the infertility?
A) Excessive estrogen production from Sertoli cells causing
spermatogenic arrest
B) Germ cell aplasia due to progressive degeneration of
seminiferous tubules
, C) Autoimmune orchitis leading to anti-sperm antibody
formation
D) Hypothalamic-pituitary dysfunction with FSH and LH
suppression
Answer: B. Klinefelter syndrome (47,XXY) results from meiotic
nondisjunction. The extra X chromosome leads to progressive
hyalinization and fibrosis of seminiferous tubules, with germ cell
aplasia (absence of spermatogonia). This directly causes
azoospermia and infertility. Testosterone levels are often low, and
FSH is elevated (not suppressed). Gynecomastia results from
increased estradiol/testosterone ratio due to peripheral
aromatization of androgens.
4. A 40-year-old patient arrives at the emergency department
following a motor vehicle accident. The patient was initially alert
and conversant but has now become lethargic with a declining
level of consciousness. Vital signs show hypertension and
bradycardia. Which pathophysiologic process is most likely
occurring?
A) Subdural hematoma with slow venous bleeding causing
gradual neurologic decline
B) Epidural hematoma with arterial bleeding, lucid interval,
and Cushing's triad
C) Diffuse axonal injury from rotational acceleration-
deceleration forces
D) Subarachnoid hemorrhage from ruptured berry aneurysm
Answer: B. The classic lucid interval followed by neurologic
decline, with hypertension/bradycardia (Cushing's triad), is
characteristic of epidural hematoma, typically from middle
, meningeal artery rupture. Venous bleeding (subdural) typically
produces a slower, more gradual decline without a clear lucid
interval. Diffuse axonal injury presents with immediate coma
without lucid interval.
5. A 35-year-old pregnant woman undergoes prenatal screening.
Maternal serum alpha-fetoprotein (MSAFP) is significantly
elevated. Which fetal condition should be suspected as the most
likely cause of this finding?
A) Trisomy 21 (Down syndrome)
B) Anencephaly (neural tube defect)
C) Turner syndrome (45,XO)
D) Cystic fibrosis
Answer: B. Elevated MSAFP is a screening marker for open neural
tube defects (e.g., anencephaly, spina bifida). Fetal serum AFP
leaks into amniotic fluid and then into maternal circulation when
the neural tube fails to close properly. Low MSAFP is associated
with trisomy 21. Turner syndrome and cystic fibrosis are not
reliably detected by MSAFP screening alone.
6. A 55-year-old male with a 40-pack-year smoking history
presents with a new cough, hemoptysis, and weight loss. Biopsy of
a lung mass reveals small cell carcinoma. Paraneoplastic syndrome
leads to elevated ACTH secretion. Which electrolyte disturbance is
most expected?
A) Hyperkalemia
B) Hyponatremia
C) Hypercalcemia
D) Hypomagnesemia
Pathophysiology Exam (Latest 2026)
Actual Questions with Detailed
Answers and OA Readiness Practice
Exam
1. A patient with systemic lupus erythematosus (SLE) presents
with facial rash across the cheeks and nose, as well as proteinuria
on urinalysis. Which pathophysiologic mechanism best explains
this presentation?
A) Type I IgE-mediated hypersensitivity to environmental
triggers
B) Autoantibody formation leading to immune complex
deposition in tissues
C) T-cell-mediated destruction of melanocytes in the skin
D) Complement deficiency resulting in recurrent bacterial
infections
Answer: B. SLE is a systemic autoimmune disease characterized
by autoantibody formation (e.g., anti-nuclear antibodies). Immune
complexes deposit in small vessels of skin, kidneys, joints, and
serosal surfaces, leading to the classic malar rash and
glomerulonephritis (proteinuria). Type I hypersensitivity is
associated with allergic conditions (e.g., anaphylaxis), not SLE.
,2. A 30-year-old woman presents with fluctuating muscle
weakness, particularly ptosis and diplopia that worsen with
repeated eye movements but improve after rest. Acetylcholine
receptor antibodies are detected. Which cellular mechanism
underlies this condition?
A) Presynaptic calcium channel blockade preventing
neurotransmitter release
B) Postsynaptic nicotinic acetylcholine receptor destruction
by autoantibodies
C) Impaired axonal conduction velocity due to demyelination
D) Genetic defect in dystrophin protein leading to muscle
fiber necrosis
Answer: B. The presentation describes myasthenia gravis, an
autoimmune disorder in which autoantibodies target and destroy
postsynaptic nicotinic ACh receptors at the neuromuscular
junction. This reduces available receptors, causing fatigable
weakness that improves with rest. Option A describes Lambert-
Eaton syndrome, option C describes multiple sclerosis, and option
D describes Duchenne muscular dystrophy.
3. A 25-year-old man is evaluated for infertility. Physical exam
reveals small, firm testes and gynecomastia. Karyotype analysis
shows 47,XXY. Which pathophysiologic consequence most directly
explains the infertility?
A) Excessive estrogen production from Sertoli cells causing
spermatogenic arrest
B) Germ cell aplasia due to progressive degeneration of
seminiferous tubules
, C) Autoimmune orchitis leading to anti-sperm antibody
formation
D) Hypothalamic-pituitary dysfunction with FSH and LH
suppression
Answer: B. Klinefelter syndrome (47,XXY) results from meiotic
nondisjunction. The extra X chromosome leads to progressive
hyalinization and fibrosis of seminiferous tubules, with germ cell
aplasia (absence of spermatogonia). This directly causes
azoospermia and infertility. Testosterone levels are often low, and
FSH is elevated (not suppressed). Gynecomastia results from
increased estradiol/testosterone ratio due to peripheral
aromatization of androgens.
4. A 40-year-old patient arrives at the emergency department
following a motor vehicle accident. The patient was initially alert
and conversant but has now become lethargic with a declining
level of consciousness. Vital signs show hypertension and
bradycardia. Which pathophysiologic process is most likely
occurring?
A) Subdural hematoma with slow venous bleeding causing
gradual neurologic decline
B) Epidural hematoma with arterial bleeding, lucid interval,
and Cushing's triad
C) Diffuse axonal injury from rotational acceleration-
deceleration forces
D) Subarachnoid hemorrhage from ruptured berry aneurysm
Answer: B. The classic lucid interval followed by neurologic
decline, with hypertension/bradycardia (Cushing's triad), is
characteristic of epidural hematoma, typically from middle
, meningeal artery rupture. Venous bleeding (subdural) typically
produces a slower, more gradual decline without a clear lucid
interval. Diffuse axonal injury presents with immediate coma
without lucid interval.
5. A 35-year-old pregnant woman undergoes prenatal screening.
Maternal serum alpha-fetoprotein (MSAFP) is significantly
elevated. Which fetal condition should be suspected as the most
likely cause of this finding?
A) Trisomy 21 (Down syndrome)
B) Anencephaly (neural tube defect)
C) Turner syndrome (45,XO)
D) Cystic fibrosis
Answer: B. Elevated MSAFP is a screening marker for open neural
tube defects (e.g., anencephaly, spina bifida). Fetal serum AFP
leaks into amniotic fluid and then into maternal circulation when
the neural tube fails to close properly. Low MSAFP is associated
with trisomy 21. Turner syndrome and cystic fibrosis are not
reliably detected by MSAFP screening alone.
6. A 55-year-old male with a 40-pack-year smoking history
presents with a new cough, hemoptysis, and weight loss. Biopsy of
a lung mass reveals small cell carcinoma. Paraneoplastic syndrome
leads to elevated ACTH secretion. Which electrolyte disturbance is
most expected?
A) Hyperkalemia
B) Hyponatremia
C) Hypercalcemia
D) Hypomagnesemia
