BIOL 252 Human Anatomy & Physiology II w/Lab | Module 5
EXAM with Questions and Answers/Plus a Rationale
Updated 2026 A+/Instant Download PDF
EXAM COVERAGE
1. Endocrine System: Glands, Hormones, and Target Tissues
2. Mechanisms of Hormone Action (Steroid vs. Non-steroid)
3. Hypothalamic-Pituitary Axis Regulation
4. Blood Chemistry and Endocrine Feedback Loops
5. Endocrine Pathophysiology and Clinical Correlations
1. A patient presents with hypercalcemia and hypophosphatemia. Laboratory results indicate
elevated parathyroid hormone (PTH) levels. Which of the following best describes the
physiological mechanism responsible for this presentation?
A. PTH directly stimulates the thyroid gland to increase calcitonin secretion.
B. PTH increases osteoclast activity and enhances renal reabsorption of calcium.
C. PTH inhibits the activation of Vitamin D in the kidneys, leading to decreased intestinal
calcium absorption.
D. PTH promotes the excretion of calcium in the distal convoluted tubules of the nephron.
Answer: B
CORRECT ANSWER : B
Rationale: PTH acts to increase serum calcium levels by stimulating osteoclast-mediated bone
resorption and increasing renal calcium reabsorption. Option A is incorrect because calcitonin
opposes PTH; Option C is incorrect because PTH stimulates Vitamin D activation to increase
absorption; Option D is incorrect because PTH inhibits, rather than promotes, calcium
excretion.
,2. A clinician is evaluating a patient with signs of central diabetes insipidus. Which hormonal
deficiency is the primary cause of this condition, and what is its physiological effect?
A. Deficiency in aldosterone, leading to excessive sodium retention.
B. Deficiency in antidiuretic hormone (ADH), leading to inability to concentrate urine.
C. Deficiency in insulin, leading to osmotic diuresis.
D. Deficiency in cortisol, leading to impaired water excretion.
Answer: B
CORRECT ANSWER : B
Rationale: Central diabetes insipidus is caused by insufficient secretion of ADH (vasopressin)
from the posterior pituitary, preventing the insertion of aquaporins into the collecting ducts.
Option A relates to mineralocorticoids; Option C relates to diabetes mellitus; Option D relates
to adrenal insufficiency.
3. A patient demonstrates signs of Graves' disease. What is the molecular basis for this autoimmune
condition?
A. Destruction of the follicular cells of the thyroid by cytotoxic T-cells.
B. Production of thyroid-stimulating immunoglobulins (TSI) that mimic TSH.
C. Excessive dietary iodine intake causing thyroid hypertrophy.
D. Inadequate secretion of TSH-releasing hormone from the hypothalamus.
Answer: B
CORRECT ANSWER : B
Rationale: Graves' disease is characterized by TSI antibodies that bind to and activate TSH
receptors, resulting in continuous thyroid hormone production independent of negative feedback.
Option A describes Hashimoto’s thyroiditis; Options C and D do not account for the
autoimmune nature of the disease.
4. A patient with a tumor of the adrenal cortex exhibits hypersecretion of aldosterone. Which of the
following clinical findings would most likely be observed?
A. Hyperkalemia and severe hypotension.
B. Metabolic acidosis and elevated plasma renin levels.
, C. Hypokalemia and hypertension due to excessive sodium retention.
D. Hyponatremia and muscle weakness.
Answer: C
CORRECT ANSWER : C
Rationale: Aldosterone promotes sodium retention and potassium excretion in the kidneys.
Excessive levels lead to hypernatremia-induced hypertension and hypokalemia. Options A, B,
and D are incorrect because they describe hypoaldosteronism or states not consistent with
primary hyperaldosteronism.
5. During a stress response, the hypothalamus stimulates the anterior pituitary to release ACTH.
What is the direct effect of this hormone on the adrenal gland?
A. Stimulation of the adrenal medulla to release epinephrine.
B. Stimulation of the zona fasciculata to secrete cortisol.
C. Inhibition of the zona glomerulosa to reduce aldosterone secretion.
D. Stimulation of the zona reticularis to produce excess catecholamines.
Answer: B
CORRECT ANSWER : B
Rationale: ACTH specifically targets the zona fasciculata of the adrenal cortex to stimulate
glucocorticoid synthesis. Option A is incorrect because the medulla is regulated by the
sympathetic nervous system; Options C and D are incorrect regarding the specific target zones.
6. A patient is diagnosed with Type 1 Diabetes Mellitus. Which mechanism explains why this
patient exhibits hyperglycemia?
A. Downregulation of insulin receptors on skeletal muscle.
B. Excessive glucagon secretion from the alpha cells of the pancreas.
C. Inability of pancreatic beta cells to produce insulin, preventing glucose uptake.
D. Impaired hepatic uptake of glucose despite adequate insulin levels.
Answer: C
CORRECT ANSWER : C
, Rationale: Type 1 diabetes is an autoimmune destruction of beta cells, leading to insulin
deficiency, which prevents glucose from entering target cells via GLUT4 transporters. Options A
and D describe insulin resistance (Type 2); Option B is a secondary effect, not the primary
cause.
7. Which of the following best describes the negative feedback loop involved in the regulation of
thyroid hormone?
A. High levels of T3/T4 stimulate the hypothalamus to release TRH.
B. High levels of T3/T4 inhibit the release of TRH and TSH.
C. TSH directly inhibits the thyroid gland from synthesizing thyroglobulin.
D. High levels of T3/T4 increase metabolic rate, which suppresses TSH secretion.
Answer: B
CORRECT ANSWER : B
Rationale: Thyroid hormone production is controlled by the hypothalamic-pituitary-thyroid axis;
elevated free T3/T4 levels exert negative feedback on both the hypothalamus and anterior
pituitary. Option A describes positive feedback; Option C is inaccurate; Option D describes the
effect of hormones rather than the feedback mechanism.
8. An increase in blood osmolarity is detected by osmoreceptors in the hypothalamus. What is the
immediate physiological response?
A. Inhibition of thirst and decrease in ADH release.
B. Release of ADH from the posterior pituitary to increase water reabsorption.
C. Stimulation of the juxtaglomerular apparatus to release renin.
D. Release of aldosterone to increase sodium excretion.
Answer: B
CORRECT ANSWER : B
Rationale: Osmoreceptors trigger the release of ADH to conserve water and dilute the blood
plasma. Option A is the opposite response; Option C is related to blood pressure regulation;
Option D would worsen osmolarity.
9. A patient is exhibiting signs of Cushing's Syndrome. Which of the following diagnostic findings
would confirm this diagnosis?
EXAM with Questions and Answers/Plus a Rationale
Updated 2026 A+/Instant Download PDF
EXAM COVERAGE
1. Endocrine System: Glands, Hormones, and Target Tissues
2. Mechanisms of Hormone Action (Steroid vs. Non-steroid)
3. Hypothalamic-Pituitary Axis Regulation
4. Blood Chemistry and Endocrine Feedback Loops
5. Endocrine Pathophysiology and Clinical Correlations
1. A patient presents with hypercalcemia and hypophosphatemia. Laboratory results indicate
elevated parathyroid hormone (PTH) levels. Which of the following best describes the
physiological mechanism responsible for this presentation?
A. PTH directly stimulates the thyroid gland to increase calcitonin secretion.
B. PTH increases osteoclast activity and enhances renal reabsorption of calcium.
C. PTH inhibits the activation of Vitamin D in the kidneys, leading to decreased intestinal
calcium absorption.
D. PTH promotes the excretion of calcium in the distal convoluted tubules of the nephron.
Answer: B
CORRECT ANSWER : B
Rationale: PTH acts to increase serum calcium levels by stimulating osteoclast-mediated bone
resorption and increasing renal calcium reabsorption. Option A is incorrect because calcitonin
opposes PTH; Option C is incorrect because PTH stimulates Vitamin D activation to increase
absorption; Option D is incorrect because PTH inhibits, rather than promotes, calcium
excretion.
,2. A clinician is evaluating a patient with signs of central diabetes insipidus. Which hormonal
deficiency is the primary cause of this condition, and what is its physiological effect?
A. Deficiency in aldosterone, leading to excessive sodium retention.
B. Deficiency in antidiuretic hormone (ADH), leading to inability to concentrate urine.
C. Deficiency in insulin, leading to osmotic diuresis.
D. Deficiency in cortisol, leading to impaired water excretion.
Answer: B
CORRECT ANSWER : B
Rationale: Central diabetes insipidus is caused by insufficient secretion of ADH (vasopressin)
from the posterior pituitary, preventing the insertion of aquaporins into the collecting ducts.
Option A relates to mineralocorticoids; Option C relates to diabetes mellitus; Option D relates
to adrenal insufficiency.
3. A patient demonstrates signs of Graves' disease. What is the molecular basis for this autoimmune
condition?
A. Destruction of the follicular cells of the thyroid by cytotoxic T-cells.
B. Production of thyroid-stimulating immunoglobulins (TSI) that mimic TSH.
C. Excessive dietary iodine intake causing thyroid hypertrophy.
D. Inadequate secretion of TSH-releasing hormone from the hypothalamus.
Answer: B
CORRECT ANSWER : B
Rationale: Graves' disease is characterized by TSI antibodies that bind to and activate TSH
receptors, resulting in continuous thyroid hormone production independent of negative feedback.
Option A describes Hashimoto’s thyroiditis; Options C and D do not account for the
autoimmune nature of the disease.
4. A patient with a tumor of the adrenal cortex exhibits hypersecretion of aldosterone. Which of the
following clinical findings would most likely be observed?
A. Hyperkalemia and severe hypotension.
B. Metabolic acidosis and elevated plasma renin levels.
, C. Hypokalemia and hypertension due to excessive sodium retention.
D. Hyponatremia and muscle weakness.
Answer: C
CORRECT ANSWER : C
Rationale: Aldosterone promotes sodium retention and potassium excretion in the kidneys.
Excessive levels lead to hypernatremia-induced hypertension and hypokalemia. Options A, B,
and D are incorrect because they describe hypoaldosteronism or states not consistent with
primary hyperaldosteronism.
5. During a stress response, the hypothalamus stimulates the anterior pituitary to release ACTH.
What is the direct effect of this hormone on the adrenal gland?
A. Stimulation of the adrenal medulla to release epinephrine.
B. Stimulation of the zona fasciculata to secrete cortisol.
C. Inhibition of the zona glomerulosa to reduce aldosterone secretion.
D. Stimulation of the zona reticularis to produce excess catecholamines.
Answer: B
CORRECT ANSWER : B
Rationale: ACTH specifically targets the zona fasciculata of the adrenal cortex to stimulate
glucocorticoid synthesis. Option A is incorrect because the medulla is regulated by the
sympathetic nervous system; Options C and D are incorrect regarding the specific target zones.
6. A patient is diagnosed with Type 1 Diabetes Mellitus. Which mechanism explains why this
patient exhibits hyperglycemia?
A. Downregulation of insulin receptors on skeletal muscle.
B. Excessive glucagon secretion from the alpha cells of the pancreas.
C. Inability of pancreatic beta cells to produce insulin, preventing glucose uptake.
D. Impaired hepatic uptake of glucose despite adequate insulin levels.
Answer: C
CORRECT ANSWER : C
, Rationale: Type 1 diabetes is an autoimmune destruction of beta cells, leading to insulin
deficiency, which prevents glucose from entering target cells via GLUT4 transporters. Options A
and D describe insulin resistance (Type 2); Option B is a secondary effect, not the primary
cause.
7. Which of the following best describes the negative feedback loop involved in the regulation of
thyroid hormone?
A. High levels of T3/T4 stimulate the hypothalamus to release TRH.
B. High levels of T3/T4 inhibit the release of TRH and TSH.
C. TSH directly inhibits the thyroid gland from synthesizing thyroglobulin.
D. High levels of T3/T4 increase metabolic rate, which suppresses TSH secretion.
Answer: B
CORRECT ANSWER : B
Rationale: Thyroid hormone production is controlled by the hypothalamic-pituitary-thyroid axis;
elevated free T3/T4 levels exert negative feedback on both the hypothalamus and anterior
pituitary. Option A describes positive feedback; Option C is inaccurate; Option D describes the
effect of hormones rather than the feedback mechanism.
8. An increase in blood osmolarity is detected by osmoreceptors in the hypothalamus. What is the
immediate physiological response?
A. Inhibition of thirst and decrease in ADH release.
B. Release of ADH from the posterior pituitary to increase water reabsorption.
C. Stimulation of the juxtaglomerular apparatus to release renin.
D. Release of aldosterone to increase sodium excretion.
Answer: B
CORRECT ANSWER : B
Rationale: Osmoreceptors trigger the release of ADH to conserve water and dilute the blood
plasma. Option A is the opposite response; Option C is related to blood pressure regulation;
Option D would worsen osmolarity.
9. A patient is exhibiting signs of Cushing's Syndrome. Which of the following diagnostic findings
would confirm this diagnosis?
