BIOL 252 Human Anatomy & Physiology II (Lab):
Module 5 Exam Review – 85 Q&A (Portage Learning,
LockDown Browser)
**SECTION I: ENDOCRINE SYSTEM FUNDAMENTALS AND HORMONE
MECHANISMS (Questions 1-20)**
1. Define hormone and distinguish between endocrine, paracrine, and autocrine
signaling.
Answer: A hormone is a chemical messenger released into extracellular fluid and
transported by blood. Endocrine signaling acts at a distance via blood, paracrine
acts on neighboring cells, and autocrine acts on the secreting cell itself.
2. Classify hormones by chemical structure and provide one example for each
class.
Answer: Amino acid derivatives (epinephrine, T4, melatonin), peptide/protein
hormones (insulin, GH, oxytocin), and steroid hormones (cortisol, testosterone,
aldosterone).
3. Explain the mechanism of action for water-soluble hormones using the cAMP
pathway.
Answer: Hormone binds G-protein-coupled receptor, activates Gs protein,
stimulates adenylate cyclase to produce cAMP, activates protein kinase A which
phosphorylates target proteins altering cellular activity.
4. Describe the mechanism of action for lipid-soluble hormones.
, Answer: Steroid and thyroid hormones diffuse through the plasma membrane,
bind cytoplasmic or nuclear receptors, form hormone-receptor complexes that
act as transcription factors altering gene expression and protein synthesis.
5. Define second messengers and list four common examples.
Answer: Intracellular signaling molecules released after receptor activation.
Common examples: cAMP, IP3, DAG, and Ca2+.
6. Explain the process of receptor down-regulation and its physiological purpose.
Answer: Prolonged exposure to high hormone levels decreases receptor number
or sensitivity, preventing overstimulation and maintaining cellular
responsiveness.
7. Differentiate between permissiveness, synergism, and antagonism in hormone
interactions.
Answer: Permissiveness: one hormone enhances responsiveness to another.
Synergism: combined effect greater than sum of individual effects. Antagonism:
one hormone opposes the action of another.
8. Describe the role of plasma transport proteins for steroid and thyroid
hormones.
Answer: They increase hormone solubility, prolong half-life in circulation, and
regulate the amount of free hormone available to enter target cells.
9. Explain humoral, hormonal, and neural stimuli for hormone release with one
example each.
Answer: Humoral (blood glucose affecting insulin), hormonal (TRH stimulating
TSH), neural (sympathetic stimulation of adrenal medulla).
10. Define tropic hormones and list the four anterior pituitary tropic hormones.
Module 5 Exam Review – 85 Q&A (Portage Learning,
LockDown Browser)
**SECTION I: ENDOCRINE SYSTEM FUNDAMENTALS AND HORMONE
MECHANISMS (Questions 1-20)**
1. Define hormone and distinguish between endocrine, paracrine, and autocrine
signaling.
Answer: A hormone is a chemical messenger released into extracellular fluid and
transported by blood. Endocrine signaling acts at a distance via blood, paracrine
acts on neighboring cells, and autocrine acts on the secreting cell itself.
2. Classify hormones by chemical structure and provide one example for each
class.
Answer: Amino acid derivatives (epinephrine, T4, melatonin), peptide/protein
hormones (insulin, GH, oxytocin), and steroid hormones (cortisol, testosterone,
aldosterone).
3. Explain the mechanism of action for water-soluble hormones using the cAMP
pathway.
Answer: Hormone binds G-protein-coupled receptor, activates Gs protein,
stimulates adenylate cyclase to produce cAMP, activates protein kinase A which
phosphorylates target proteins altering cellular activity.
4. Describe the mechanism of action for lipid-soluble hormones.
, Answer: Steroid and thyroid hormones diffuse through the plasma membrane,
bind cytoplasmic or nuclear receptors, form hormone-receptor complexes that
act as transcription factors altering gene expression and protein synthesis.
5. Define second messengers and list four common examples.
Answer: Intracellular signaling molecules released after receptor activation.
Common examples: cAMP, IP3, DAG, and Ca2+.
6. Explain the process of receptor down-regulation and its physiological purpose.
Answer: Prolonged exposure to high hormone levels decreases receptor number
or sensitivity, preventing overstimulation and maintaining cellular
responsiveness.
7. Differentiate between permissiveness, synergism, and antagonism in hormone
interactions.
Answer: Permissiveness: one hormone enhances responsiveness to another.
Synergism: combined effect greater than sum of individual effects. Antagonism:
one hormone opposes the action of another.
8. Describe the role of plasma transport proteins for steroid and thyroid
hormones.
Answer: They increase hormone solubility, prolong half-life in circulation, and
regulate the amount of free hormone available to enter target cells.
9. Explain humoral, hormonal, and neural stimuli for hormone release with one
example each.
Answer: Humoral (blood glucose affecting insulin), hormonal (TRH stimulating
TSH), neural (sympathetic stimulation of adrenal medulla).
10. Define tropic hormones and list the four anterior pituitary tropic hormones.
