APEA Pathophysiology Exam Testbank
2026 — Comprehensive Practice Exam
With Verified Answers & Complete
Rationales
**1. A 54-year-old patient with type 1 diabetes presents with
fatigue, polyuria, and fruity breath. Which laboratory finding is
most consistent with diabetic ketoacidosis (DKA)?**
A. Elevated pH
B. Decreased bicarbonate
C. Decreased potassium
D. Elevated glomerular filtration rate
**Correct answer:** B. Decreased bicarbonate
**Rationale:** In DKA, ketone bodies (acetoacetic acid and
beta-hydroxybutyric acid) are strong acids that consume
bicarbonate buffers, leading to metabolic acidosis with
decreased serum bicarbonate. pH is decreased (acidosis), not
elevated. Potassium may be normal or elevated initially due to
transcellular shifts, despite total body depletion. Glomerular
filtration rate is decreased due to dehydration .
---
,**2. A patient with an elevated thyroid-stimulating hormone
(TSH) level most likely has:**
A. Subacute thyroiditis
B. Toxic adenoma
C. Graves' disease
D. Hypothyroidism
**Correct answer:** D. Hypothyroidism
**Rationale:** In primary hypothyroidism, the thyroid gland
produces insufficient thyroid hormone, leading to decreased
negative feedback on the pituitary and a compensatory
elevation in TSH. Subacute thyroiditis, toxic adenoma, and
Graves' disease all cause hyperthyroidism, which would
suppress TSH .
---
**3. A 65-year-old patient with a history of smoking presents
with a lung mass. Biopsy reveals cells that are abnormal in
size, shape, and organization. This finding is most consistent
with:**
A. Hyperplasia
,B. Metaplasia
C. Dysplasia
D. Anaplasia
**Correct answer:** C. Dysplasia
**Rationale:** Dysplasia is characterized by abnormal changes
in cell size, shape, and organization. It is often a precancerous
condition. Hyperplasia is an increase in cell number with normal
cell appearance. Metaplasia is the reversible replacement of
one mature cell type with another. Anaplasia refers to
undifferentiated cells seen in malignant tumors .
---
**4. A 58-year-old male presents with chest pressure with
exertion that resolves with rest. He describes it as "heavy
pressure" in the substernal area radiating to the left jaw. Which
finding is most consistent with stable angina?**
A. Pain that is sharp and pleuritic, worsening with inspiration
B. Pain reproducible with palpation of the chest wall
C. Pain provoked by exertion and relieved within minutes by
rest or nitroglycerin
D. Pain constant for hours with diaphoresis and nausea
, **Correct answer:** C. Pain provoked by exertion and relieved
within minutes by rest or nitroglycerin
**Rationale:** Stable angina is characterized by chest
discomfort provoked by physical exertion or emotional stress
and relieved by rest or sublingual nitroglycerin within 5–10
minutes. Pathophysiology: fixed coronary artery stenosis
(typically >70%) leads to demand-supply mismatch during
increased oxygen demand. Pleuritic pain suggests pericarditis.
Reproducible pain with palpation suggests costochondritis.
Prolonged pain with diaphoresis suggests acute MI .
---
**5. During cardiac auscultation, you hear a mid-systolic click
followed by a late systolic murmur at the apex, best heard with
the bell. This is most consistent with:**
A. Aortic stenosis
B. Mitral valve prolapse
C. Hypertrophic cardiomyopathy
D. Tricuspid regurgitation
**Correct answer:** B. Mitral valve prolapse
**Rationale:** Mitral valve prolapse (MVP) is characterized by a
mid-systolic click (due to chordae tendineae tension) followed
2026 — Comprehensive Practice Exam
With Verified Answers & Complete
Rationales
**1. A 54-year-old patient with type 1 diabetes presents with
fatigue, polyuria, and fruity breath. Which laboratory finding is
most consistent with diabetic ketoacidosis (DKA)?**
A. Elevated pH
B. Decreased bicarbonate
C. Decreased potassium
D. Elevated glomerular filtration rate
**Correct answer:** B. Decreased bicarbonate
**Rationale:** In DKA, ketone bodies (acetoacetic acid and
beta-hydroxybutyric acid) are strong acids that consume
bicarbonate buffers, leading to metabolic acidosis with
decreased serum bicarbonate. pH is decreased (acidosis), not
elevated. Potassium may be normal or elevated initially due to
transcellular shifts, despite total body depletion. Glomerular
filtration rate is decreased due to dehydration .
---
,**2. A patient with an elevated thyroid-stimulating hormone
(TSH) level most likely has:**
A. Subacute thyroiditis
B. Toxic adenoma
C. Graves' disease
D. Hypothyroidism
**Correct answer:** D. Hypothyroidism
**Rationale:** In primary hypothyroidism, the thyroid gland
produces insufficient thyroid hormone, leading to decreased
negative feedback on the pituitary and a compensatory
elevation in TSH. Subacute thyroiditis, toxic adenoma, and
Graves' disease all cause hyperthyroidism, which would
suppress TSH .
---
**3. A 65-year-old patient with a history of smoking presents
with a lung mass. Biopsy reveals cells that are abnormal in
size, shape, and organization. This finding is most consistent
with:**
A. Hyperplasia
,B. Metaplasia
C. Dysplasia
D. Anaplasia
**Correct answer:** C. Dysplasia
**Rationale:** Dysplasia is characterized by abnormal changes
in cell size, shape, and organization. It is often a precancerous
condition. Hyperplasia is an increase in cell number with normal
cell appearance. Metaplasia is the reversible replacement of
one mature cell type with another. Anaplasia refers to
undifferentiated cells seen in malignant tumors .
---
**4. A 58-year-old male presents with chest pressure with
exertion that resolves with rest. He describes it as "heavy
pressure" in the substernal area radiating to the left jaw. Which
finding is most consistent with stable angina?**
A. Pain that is sharp and pleuritic, worsening with inspiration
B. Pain reproducible with palpation of the chest wall
C. Pain provoked by exertion and relieved within minutes by
rest or nitroglycerin
D. Pain constant for hours with diaphoresis and nausea
, **Correct answer:** C. Pain provoked by exertion and relieved
within minutes by rest or nitroglycerin
**Rationale:** Stable angina is characterized by chest
discomfort provoked by physical exertion or emotional stress
and relieved by rest or sublingual nitroglycerin within 5–10
minutes. Pathophysiology: fixed coronary artery stenosis
(typically >70%) leads to demand-supply mismatch during
increased oxygen demand. Pleuritic pain suggests pericarditis.
Reproducible pain with palpation suggests costochondritis.
Prolonged pain with diaphoresis suggests acute MI .
---
**5. During cardiac auscultation, you hear a mid-systolic click
followed by a late systolic murmur at the apex, best heard with
the bell. This is most consistent with:**
A. Aortic stenosis
B. Mitral valve prolapse
C. Hypertrophic cardiomyopathy
D. Tricuspid regurgitation
**Correct answer:** B. Mitral valve prolapse
**Rationale:** Mitral valve prolapse (MVP) is characterized by a
mid-systolic click (due to chordae tendineae tension) followed
