BIO 242: Comprehensive Human Anatomy &
Physiology II Examination
Course Code: BIO 242 | Total Questions: 60 | Formatted with Explanations and Green
Highlighted Rationales
Section 1: Endocrine System
1. Which hormone is released by the posterior pituitary in response to increased blood
osmolality and acts on kidney collecting ducts to increase water reabsorption?
A. Aldosterone
B. Antidiuretic hormone (Vasopressin)
C. Oxytocin
D. Atrial natriuretic peptide
Correct Answer: B. Antidiuretic hormone (Vasopressin)
Rationale: Antidiuretic hormone (ADH) is synthesized in the hypothalamus, stored and
released by the posterior pituitary, and promotes water retention by inserting aquaporin-2
channels into the late distal tubule and collecting duct cells of the kidney.
2. A patient presents with hypercalcemia, kidney stones, and bone decalcification.
Plasma hormone analysis reveals elevated levels of which of the following?
A. Calcitonin
B. Parathyroid hormone
C. Thyroid-stimulating hormone
D. Growth hormone
Correct Answer: B. Parathyroid hormone
Rationale: Hyperparathyroidism leads to excess parathyroid hormone (PTH) production,
which stimulates osteoclasts to reabsorb bone matrix, increases intestinal calcium
absorption (via activation of vitamin D), and promotes renal calcium reabsorption, resulting
in classic symptoms described as "bones, stones, and groans."
3. Which endocrine zone of the adrenal cortex is responsible for synthesizing
mineralocorticoids such as aldosterone?
A. Zona fasciculata
B. Zona reticularis
, C. Zona glomerulosa
D. Adrenal medulla
Correct Answer: C. Zona glomerulosa
Rationale: The adrenal cortex consists of three layers from outer to inner: Zona
glomerulosa (produces mineralocorticoids like aldosterone), Zona fasciculata (produces
glucocorticoids like cortisol), and Zona reticularis (produces gonadocorticoids/androgens).
4. Which mechanism of action is characteristic of steroid hormones?
A. Binding to G-protein coupled receptors to stimulate cAMP production
B. Binding to intracellular receptors to direct gene transcription
C. Direct opening of ligand-gated ion channels on the plasma membrane
D. Activation of receptor tyrosine kinase cascades
Correct Answer: B. Binding to intracellular receptors to direct gene transcription
Rationale: Steroid hormones are lipid-soluble and diffuse across the phospholipid bilayer to
bind intracellular (cytoplasmic or nuclear) receptors, forming hormone-receptor complexes
that bind to specific DNA sequences to regulate gene expression.
5. Insulin lowers blood glucose levels through all of the following pathways EXCEPT:
A. Translocation of GLUT4 transporters to cell membranes in skeletal muscle and adipose
tissue
B. Stimulating glycogenesis in the liver
C. Promoting gluconeogenesis in hepatocytes
D. Inhibiting lipolysis in adipose tissue
Correct Answer: C. Promoting gluconeogenesis in hepatocytes
Rationale: Insulin inhibits gluconeogenesis (the synthesis of glucose from non-carbohydrate
sources) and glycogenolysis. Glucagon promotes gluconeogenesis and glycogenolysis to
raise blood glucose levels.
6. Which anterior pituitary cell type synthesizes and secretes Thyroid-Stimulating
Hormone (TSH)?
A. Somatotrophs
B. Lactotrophs
C. Thyrotrophs
D. Corticotrophs
Correct Answer: C. Thyrotrophs
, Rationale: Thyrotrophs account for approximately 5% of anterior pituitary cells and release
TSH in response to hypothalamic Thyrotropin-Releasing Hormone (TRH).
7. The hypophyseal portal system directly connects the primary capillary plexus in the
hypothalamus to the secondary capillary plexus located in which organ or tissue?
A. Posterior pituitary (Neurohypophysis)
B. Anterior pituitary (Adenohypophysis)
C. Adrenal cortex
D. Thyroid gland
Correct Answer: B. Anterior pituitary (Adenohypophysis)
Rationale: The hypophyseal portal system allows hypothalamic releasing and inhibiting
hormones to travel directly to the anterior pituitary without first circulating through the
systemic vascular system.
8. What is the primary stimulus for the release of Atrial Natriuretic Peptide (ANP)?
A. Hypovolemia
B. Stretch of the cardiac atrial walls due to elevated venous return and blood volume
C. High blood potassium concentrations
D. Sympathetic nerve stimulation to the kidney
Correct Answer: B. Stretch of the cardiac atrial walls due to elevated venous return
and blood volume
Rationale: ANP is released by atrial myocytes when blood volume and pressure rise,
promoting natriuresis (sodium loss), diuresis (water loss), and vasodilation to lower blood
pressure.
Section 2: Cardiovascular System - Blood & Heart
9. Which plasma protein is the primary contributor to plasma colloid osmotic pressure
(oncotic pressure)?
A. Fibrinogen
B. Gamma globulin
C. Albumin
D. Alpha-1 antitrypsin
Correct Answer: C. Albumin
Rationale: Albumin accounts for ~60% of total plasma protein content and provides roughly
Physiology II Examination
Course Code: BIO 242 | Total Questions: 60 | Formatted with Explanations and Green
Highlighted Rationales
Section 1: Endocrine System
1. Which hormone is released by the posterior pituitary in response to increased blood
osmolality and acts on kidney collecting ducts to increase water reabsorption?
A. Aldosterone
B. Antidiuretic hormone (Vasopressin)
C. Oxytocin
D. Atrial natriuretic peptide
Correct Answer: B. Antidiuretic hormone (Vasopressin)
Rationale: Antidiuretic hormone (ADH) is synthesized in the hypothalamus, stored and
released by the posterior pituitary, and promotes water retention by inserting aquaporin-2
channels into the late distal tubule and collecting duct cells of the kidney.
2. A patient presents with hypercalcemia, kidney stones, and bone decalcification.
Plasma hormone analysis reveals elevated levels of which of the following?
A. Calcitonin
B. Parathyroid hormone
C. Thyroid-stimulating hormone
D. Growth hormone
Correct Answer: B. Parathyroid hormone
Rationale: Hyperparathyroidism leads to excess parathyroid hormone (PTH) production,
which stimulates osteoclasts to reabsorb bone matrix, increases intestinal calcium
absorption (via activation of vitamin D), and promotes renal calcium reabsorption, resulting
in classic symptoms described as "bones, stones, and groans."
3. Which endocrine zone of the adrenal cortex is responsible for synthesizing
mineralocorticoids such as aldosterone?
A. Zona fasciculata
B. Zona reticularis
, C. Zona glomerulosa
D. Adrenal medulla
Correct Answer: C. Zona glomerulosa
Rationale: The adrenal cortex consists of three layers from outer to inner: Zona
glomerulosa (produces mineralocorticoids like aldosterone), Zona fasciculata (produces
glucocorticoids like cortisol), and Zona reticularis (produces gonadocorticoids/androgens).
4. Which mechanism of action is characteristic of steroid hormones?
A. Binding to G-protein coupled receptors to stimulate cAMP production
B. Binding to intracellular receptors to direct gene transcription
C. Direct opening of ligand-gated ion channels on the plasma membrane
D. Activation of receptor tyrosine kinase cascades
Correct Answer: B. Binding to intracellular receptors to direct gene transcription
Rationale: Steroid hormones are lipid-soluble and diffuse across the phospholipid bilayer to
bind intracellular (cytoplasmic or nuclear) receptors, forming hormone-receptor complexes
that bind to specific DNA sequences to regulate gene expression.
5. Insulin lowers blood glucose levels through all of the following pathways EXCEPT:
A. Translocation of GLUT4 transporters to cell membranes in skeletal muscle and adipose
tissue
B. Stimulating glycogenesis in the liver
C. Promoting gluconeogenesis in hepatocytes
D. Inhibiting lipolysis in adipose tissue
Correct Answer: C. Promoting gluconeogenesis in hepatocytes
Rationale: Insulin inhibits gluconeogenesis (the synthesis of glucose from non-carbohydrate
sources) and glycogenolysis. Glucagon promotes gluconeogenesis and glycogenolysis to
raise blood glucose levels.
6. Which anterior pituitary cell type synthesizes and secretes Thyroid-Stimulating
Hormone (TSH)?
A. Somatotrophs
B. Lactotrophs
C. Thyrotrophs
D. Corticotrophs
Correct Answer: C. Thyrotrophs
, Rationale: Thyrotrophs account for approximately 5% of anterior pituitary cells and release
TSH in response to hypothalamic Thyrotropin-Releasing Hormone (TRH).
7. The hypophyseal portal system directly connects the primary capillary plexus in the
hypothalamus to the secondary capillary plexus located in which organ or tissue?
A. Posterior pituitary (Neurohypophysis)
B. Anterior pituitary (Adenohypophysis)
C. Adrenal cortex
D. Thyroid gland
Correct Answer: B. Anterior pituitary (Adenohypophysis)
Rationale: The hypophyseal portal system allows hypothalamic releasing and inhibiting
hormones to travel directly to the anterior pituitary without first circulating through the
systemic vascular system.
8. What is the primary stimulus for the release of Atrial Natriuretic Peptide (ANP)?
A. Hypovolemia
B. Stretch of the cardiac atrial walls due to elevated venous return and blood volume
C. High blood potassium concentrations
D. Sympathetic nerve stimulation to the kidney
Correct Answer: B. Stretch of the cardiac atrial walls due to elevated venous return
and blood volume
Rationale: ANP is released by atrial myocytes when blood volume and pressure rise,
promoting natriuresis (sodium loss), diuresis (water loss), and vasodilation to lower blood
pressure.
Section 2: Cardiovascular System - Blood & Heart
9. Which plasma protein is the primary contributor to plasma colloid osmotic pressure
(oncotic pressure)?
A. Fibrinogen
B. Gamma globulin
C. Albumin
D. Alpha-1 antitrypsin
Correct Answer: C. Albumin
Rationale: Albumin accounts for ~60% of total plasma protein content and provides roughly
