A&P 2 STRAIGHTERLINE FINAL EXAM 2026/2027 | 100%
Correct Answers with Complete Solutions | Human Anatomy
& Physiology II | Clinical Correlations | Homeostasis | Pass
Guaranteed - A+ Graded
Domain 1: Endocrine System (15 Questions)
Q1: A 45-year-old female patient presents with fatigue, weight gain, cold intolerance, and
a goiter. Laboratory tests reveal elevated TSH and decreased free T4. Which endocrine
disorder and underlying pathophysiology best explain these findings?
A. Primary hypothyroidism due to autoimmune destruction of thyroid tissue
(Hashimoto's thyroiditis), resulting in decreased negative feedback on the anterior
pituitary and compensatory TSH elevation [CORRECT]
B. Secondary hyperthyroidism due to TSH-secreting pituitary adenoma causing
excessive thyroid hormone production
C. Primary hyperparathyroidism with elevated PTH causing metabolic disturbances and
thyroid enlargement
D. Cushing's syndrome with excess cortisol suppressing thyroid function through
competitive inhibition
Correct Answer: A
Rationale: The clinical triad of hypothyroid symptoms (fatigue, weight gain, cold
intolerance) with elevated TSH and low T4 indicates primary hypothyroidism. In
Hashimoto's thyroiditis, autoimmune destruction of thyroid follicles reduces T4/T3
production, decreasing negative feedback on the hypothalamus-pituitary axis. The
anterior pituitary compensates by increasing TSH secretion, causing thyroid
enlargement (goiter). Option B is incorrect because TSH-secreting adenomas cause
hyperthyroidism (heat intolerance, weight loss) with elevated T4. Option C describes
,parathyroid dysfunction unrelated to thyroid hormone levels. Option D incorrectly
suggests cortisol suppresses thyroid function through competitive inhibition—cortisol
excess causes Cushingoid features (central obesity, moon facies) distinct from these
symptoms.
Q2: A patient with Cushing's syndrome presents with central obesity, moon facies,
buffalo hump, and thin skin with easy bruising. Which hormone is elevated, and which
adrenal zone is primarily responsible?
A. Cortisol; zona fasciculata of the adrenal cortex [CORRECT]
B. Aldosterone; zona glomerulosa of the adrenal cortex
C. Epinephrine; adrenal medulla
D. Androgens; zona reticularis of the adrenal cortex
Correct Answer: A
Rationale: Cushing's syndrome results from chronic excess glucocorticoids (cortisol).
Cortisol is synthesized in the zona fasciculata under ACTH stimulation. The clinical
features reflect cortisol's metabolic effects: protein catabolism (thin skin, muscle
wasting), lipolysis and redistribution (central obesity, buffalo hump), and
anti-inflammatory effects (easy bruising, poor wound healing). Option B (aldosterone)
causes Conn's syndrome with hypertension and hypokalemia. Option C (epinephrine)
causes pheochromocytoma with episodic hypertension, sweating, and anxiety. Option D
(androgens) causes virilization in females but not the characteristic Cushingoid body
habitus.
Q3: Which hypothalamic-pituitary axis correctly describes the relationship between
releasing hormones, anterior pituitary tropic hormones, and target gland hormones?
,A. TRH (hypothalamus) → TSH (anterior pituitary) → T3/T4 (thyroid) with negative
feedback by T3/T4 on both hypothalamus and pituitary [CORRECT]
B. CRH (hypothalamus) → ACTH (posterior pituitary) → cortisol (adrenal medulla)
C. GnRH (hypothalamus) → LH/FSH (thyroid) → estrogen/testosterone (gonads)
D. GHRH (hypothalamus) → GH (anterior pituitary) → IGF-1 (liver) with positive
feedback only
Correct Answer: A
Rationale: The hypothalamic-pituitary-thyroid axis demonstrates classic hierarchical
control: hypothalamic TRH stimulates anterior pituitary thyrotrophs to release TSH,
which stimulates thyroid follicular cells to produce T3/T4. Thyroid hormones exert
negative feedback on both hypothalamic TRH secretion and pituitary TSH release.
Option B is incorrect because ACTH targets the adrenal cortex (not medulla) and the
posterior pituitary releases ADH/oxytocin, not ACTH. Option C incorrectly states
LH/FSH come from the thyroid rather than anterior pituitary. Option D is incorrect
because GH/IGF-1 feedback is primarily negative, not positive.
Q4: A patient with Type 1 Diabetes Mellitus experiences polyuria, polydipsia, and
polyphagia. Which pathophysiological mechanism explains the polyuria (excessive urine
production)?
A. Hyperglycemia exceeds renal glucose reabsorption capacity (transport maximum),
causing osmotic diuresis as glucose acts as an osmotic agent in renal tubules
[CORRECT]
B. Insulin deficiency directly stimulates ADH secretion from the posterior pituitary
C. Glucagon excess inhibits aldosterone secretion, reducing water reabsorption
D. Ketone bodies compete with sodium for reabsorption in the proximal tubule
Correct Answer: A
Rationale: In uncontrolled diabetes, blood glucose exceeds the renal threshold (~180
mg/dL) and transport maximum for glucose reabsorption. Unreabsorbed glucose
, remains in the tubular lumen, creating osmotic pressure that opposes water
reabsorption (osmotic diuresis). This produces large volumes of dilute urine (polyuria),
triggering compensatory thirst (polydipsia). Option B is incorrect—insulin deficiency
doesn't stimulate ADH; in fact, diabetes insipidus (ADH deficiency) causes polyuria
through different mechanisms. Option C incorrectly links glucagon to aldosterone
inhibition. Option D describes a non-existent mechanism; while ketonuria occurs, it
doesn't cause polyuria through sodium competition.
Q5: Which hormone is correctly matched with its mechanism of action and intracellular
receptor location?
A. Cortisol (steroid hormone) → diffuses through plasma membrane → binds
intracellular receptor → hormone-receptor complex binds DNA response elements →
alters gene transcription [CORRECT]
B. Insulin (peptide hormone) → diffuses through plasma membrane → binds nuclear
receptor → direct gene activation
C. Epinephrine (amine hormone) → binds intracellular receptor → activates second
messenger system directly without membrane receptor
D. Thyroid hormones (amine-derived) → bind cell surface receptor → activate G-protein
cascade
Correct Answer: A
Rationale: Cortisol, as a steroid hormone (lipid-soluble), diffuses through the plasma
membrane and binds intracellular receptors (cytoplasmic or nuclear). The
hormone-receptor complex acts as a transcription factor, binding specific DNA
sequences (hormone response elements) to regulate gene expression. Option B is
incorrect—insulin (peptide) cannot cross membranes and binds cell surface receptors
(tyrosine kinase). Option C is incorrect—epinephrine binds cell surface adrenergic
receptors (G-protein coupled). Option D is incorrect—while thyroid hormones are
Correct Answers with Complete Solutions | Human Anatomy
& Physiology II | Clinical Correlations | Homeostasis | Pass
Guaranteed - A+ Graded
Domain 1: Endocrine System (15 Questions)
Q1: A 45-year-old female patient presents with fatigue, weight gain, cold intolerance, and
a goiter. Laboratory tests reveal elevated TSH and decreased free T4. Which endocrine
disorder and underlying pathophysiology best explain these findings?
A. Primary hypothyroidism due to autoimmune destruction of thyroid tissue
(Hashimoto's thyroiditis), resulting in decreased negative feedback on the anterior
pituitary and compensatory TSH elevation [CORRECT]
B. Secondary hyperthyroidism due to TSH-secreting pituitary adenoma causing
excessive thyroid hormone production
C. Primary hyperparathyroidism with elevated PTH causing metabolic disturbances and
thyroid enlargement
D. Cushing's syndrome with excess cortisol suppressing thyroid function through
competitive inhibition
Correct Answer: A
Rationale: The clinical triad of hypothyroid symptoms (fatigue, weight gain, cold
intolerance) with elevated TSH and low T4 indicates primary hypothyroidism. In
Hashimoto's thyroiditis, autoimmune destruction of thyroid follicles reduces T4/T3
production, decreasing negative feedback on the hypothalamus-pituitary axis. The
anterior pituitary compensates by increasing TSH secretion, causing thyroid
enlargement (goiter). Option B is incorrect because TSH-secreting adenomas cause
hyperthyroidism (heat intolerance, weight loss) with elevated T4. Option C describes
,parathyroid dysfunction unrelated to thyroid hormone levels. Option D incorrectly
suggests cortisol suppresses thyroid function through competitive inhibition—cortisol
excess causes Cushingoid features (central obesity, moon facies) distinct from these
symptoms.
Q2: A patient with Cushing's syndrome presents with central obesity, moon facies,
buffalo hump, and thin skin with easy bruising. Which hormone is elevated, and which
adrenal zone is primarily responsible?
A. Cortisol; zona fasciculata of the adrenal cortex [CORRECT]
B. Aldosterone; zona glomerulosa of the adrenal cortex
C. Epinephrine; adrenal medulla
D. Androgens; zona reticularis of the adrenal cortex
Correct Answer: A
Rationale: Cushing's syndrome results from chronic excess glucocorticoids (cortisol).
Cortisol is synthesized in the zona fasciculata under ACTH stimulation. The clinical
features reflect cortisol's metabolic effects: protein catabolism (thin skin, muscle
wasting), lipolysis and redistribution (central obesity, buffalo hump), and
anti-inflammatory effects (easy bruising, poor wound healing). Option B (aldosterone)
causes Conn's syndrome with hypertension and hypokalemia. Option C (epinephrine)
causes pheochromocytoma with episodic hypertension, sweating, and anxiety. Option D
(androgens) causes virilization in females but not the characteristic Cushingoid body
habitus.
Q3: Which hypothalamic-pituitary axis correctly describes the relationship between
releasing hormones, anterior pituitary tropic hormones, and target gland hormones?
,A. TRH (hypothalamus) → TSH (anterior pituitary) → T3/T4 (thyroid) with negative
feedback by T3/T4 on both hypothalamus and pituitary [CORRECT]
B. CRH (hypothalamus) → ACTH (posterior pituitary) → cortisol (adrenal medulla)
C. GnRH (hypothalamus) → LH/FSH (thyroid) → estrogen/testosterone (gonads)
D. GHRH (hypothalamus) → GH (anterior pituitary) → IGF-1 (liver) with positive
feedback only
Correct Answer: A
Rationale: The hypothalamic-pituitary-thyroid axis demonstrates classic hierarchical
control: hypothalamic TRH stimulates anterior pituitary thyrotrophs to release TSH,
which stimulates thyroid follicular cells to produce T3/T4. Thyroid hormones exert
negative feedback on both hypothalamic TRH secretion and pituitary TSH release.
Option B is incorrect because ACTH targets the adrenal cortex (not medulla) and the
posterior pituitary releases ADH/oxytocin, not ACTH. Option C incorrectly states
LH/FSH come from the thyroid rather than anterior pituitary. Option D is incorrect
because GH/IGF-1 feedback is primarily negative, not positive.
Q4: A patient with Type 1 Diabetes Mellitus experiences polyuria, polydipsia, and
polyphagia. Which pathophysiological mechanism explains the polyuria (excessive urine
production)?
A. Hyperglycemia exceeds renal glucose reabsorption capacity (transport maximum),
causing osmotic diuresis as glucose acts as an osmotic agent in renal tubules
[CORRECT]
B. Insulin deficiency directly stimulates ADH secretion from the posterior pituitary
C. Glucagon excess inhibits aldosterone secretion, reducing water reabsorption
D. Ketone bodies compete with sodium for reabsorption in the proximal tubule
Correct Answer: A
Rationale: In uncontrolled diabetes, blood glucose exceeds the renal threshold (~180
mg/dL) and transport maximum for glucose reabsorption. Unreabsorbed glucose
, remains in the tubular lumen, creating osmotic pressure that opposes water
reabsorption (osmotic diuresis). This produces large volumes of dilute urine (polyuria),
triggering compensatory thirst (polydipsia). Option B is incorrect—insulin deficiency
doesn't stimulate ADH; in fact, diabetes insipidus (ADH deficiency) causes polyuria
through different mechanisms. Option C incorrectly links glucagon to aldosterone
inhibition. Option D describes a non-existent mechanism; while ketonuria occurs, it
doesn't cause polyuria through sodium competition.
Q5: Which hormone is correctly matched with its mechanism of action and intracellular
receptor location?
A. Cortisol (steroid hormone) → diffuses through plasma membrane → binds
intracellular receptor → hormone-receptor complex binds DNA response elements →
alters gene transcription [CORRECT]
B. Insulin (peptide hormone) → diffuses through plasma membrane → binds nuclear
receptor → direct gene activation
C. Epinephrine (amine hormone) → binds intracellular receptor → activates second
messenger system directly without membrane receptor
D. Thyroid hormones (amine-derived) → bind cell surface receptor → activate G-protein
cascade
Correct Answer: A
Rationale: Cortisol, as a steroid hormone (lipid-soluble), diffuses through the plasma
membrane and binds intracellular receptors (cytoplasmic or nuclear). The
hormone-receptor complex acts as a transcription factor, binding specific DNA
sequences (hormone response elements) to regulate gene expression. Option B is
incorrect—insulin (peptide) cannot cross membranes and binds cell surface receptors
(tyrosine kinase). Option C is incorrect—epinephrine binds cell surface adrenergic
receptors (G-protein coupled). Option D is incorrect—while thyroid hormones are
