Q1. What is the primary difference between endocrine and exocrine glands?
ANSWER Endocrine glands secrete hormones directly into the bloodstream;
exocrine glands secrete through ducts to a surface.
Q2. What is a hormone? ANSWER A chemical messenger secreted by
endocrine cells that travels through the blood to target cells.
Q3. What are the two main chemical classes of hormones? ANSWER Steroid
hormones (lipid-based) and amino acid–based hormones (water-soluble).
Q4. Where do steroid hormones come from structurally? ANSWER They are
derived from cholesterol.
Q5. Can steroid hormones pass through the plasma membrane? ANSWER
Yes, because they are lipid-soluble.
Q6. Where do steroid hormone receptors typically reside? ANSWER Inside
the cell (cytoplasm or nucleus).
Q7. How do amino acid–based hormones exert their effects? ANSWER They
bind to receptors on the cell surface and use second messenger systems (e.g.,
cAMP or PIP-calcium).
Q8. What is the cAMP second messenger pathway? ANSWER A hormone
binds a receptor → activates G protein → activates adenylate cyclase →
converts ATP to cAMP → activates protein kinases → cellular response.
Q9. Name two hormones that use the cAMP mechanism. ANSWER
Epinephrine and glucagon.
Q10. What is up-regulation? ANSWER An increase in the number of receptors
on a target cell in response to low hormone levels.
Q11. What is down-regulation? ANSWER A decrease in the number of
receptors in response to persistently high hormone levels.
,Q12. What is a paracrine secretion? ANSWER A chemical that acts on
neighboring cells (local effect).
Q13. What is an autocrine secretion? ANSWER A chemical that acts on the
same cell that produced it.
Q14. What gland is considered the "master gland"? ANSWER The anterior
pituitary (adenohypophysis).
Q15. What structure controls the pituitary gland? ANSWER The
hypothalamus.
Q16. What are the two lobes of the pituitary gland? ANSWER Anterior
pituitary (adenohypophysis) and posterior pituitary (neurohypophysis).
Q17. What hormones are released from the posterior pituitary? ANSWER
ADH (antidiuretic hormone/vasopressin) and oxytocin.
Q18. Where are ADH and oxytocin actually produced? ANSWER In the
hypothalamus; they are stored and released from the posterior pituitary.
Q19. What does ADH do? ANSWER It promotes water reabsorption in the
kidneys, reducing urine output.
Q20. What is the function of oxytocin? ANSWER Stimulates uterine
contractions during labor and milk ejection during breastfeeding.
Q21. What are the six hormones released from the anterior pituitary?
ANSWER GH, TSH, ACTH, FSH, LH, and Prolactin.
Q22. What does TSH stand for and what does it do? ANSWER Thyroid-
stimulating hormone; it stimulates the thyroid gland to release thyroid
hormones.
Q23. What does ACTH do? ANSWER Stimulates the adrenal cortex to secrete
cortisol.
Q24. What does growth hormone (GH) do? ANSWER Stimulates growth of
body tissues, especially bone and muscle; promotes protein synthesis and fat
breakdown.
Q25. What is IGF (Insulin-like Growth Factor)? ANSWER A hormone
released by the liver in response to GH that mediates many of GH's growth-
promoting effects.
, Q26. What disorder results from excess GH in adults? ANSWER Acromegaly.
Q27. What disorder results from GH deficiency in children? ANSWER
Pituitary dwarfism.
Q28. What are the two thyroid hormones? ANSWER T3 (triiodothyronine)
and T4 (thyroxine).
Q29. What mineral is required to make thyroid hormones? ANSWER Iodine.
Q30. What is the primary effect of thyroid hormones? ANSWER Increase
metabolic rate (basal metabolic rate).
Q31. What is hypothyroidism? ANSWER Low thyroid hormone production;
symptoms include fatigue, weight gain, and cold intolerance.
Q32. What is hyperthyroidism? ANSWER Excess thyroid hormone; symptoms
include weight loss, heat intolerance, and rapid heart rate.
Q33. What is a goiter? ANSWER Enlargement of the thyroid gland, often due
to iodine deficiency or excessive TSH stimulation.
Q34. What hormone does the thyroid gland release to lower blood calcium?
ANSWER Calcitonin.
Q35. What do parathyroid glands produce? ANSWER Parathyroid hormone
(PTH).
Q36. What does PTH do to blood calcium levels? ANSWER Raises blood
calcium by stimulating osteoclasts, increasing kidney reabsorption of calcium,
and activating vitamin D.
Q37. What are the two regions of the adrenal gland? ANSWER Adrenal cortex
(outer) and adrenal medulla (inner).
Q38. What hormones does the adrenal medulla secrete? ANSWER
Epinephrine (adrenaline) and norepinephrine (noradrenaline).
Q39. What are the three classes of hormones from the adrenal cortex?
ANSWER Mineralocorticoids, glucocorticoids, and gonadocorticoids
(androgens).
Q40. What is the main mineralocorticoid? ANSWER Aldosterone.
ANSWER Endocrine glands secrete hormones directly into the bloodstream;
exocrine glands secrete through ducts to a surface.
Q2. What is a hormone? ANSWER A chemical messenger secreted by
endocrine cells that travels through the blood to target cells.
Q3. What are the two main chemical classes of hormones? ANSWER Steroid
hormones (lipid-based) and amino acid–based hormones (water-soluble).
Q4. Where do steroid hormones come from structurally? ANSWER They are
derived from cholesterol.
Q5. Can steroid hormones pass through the plasma membrane? ANSWER
Yes, because they are lipid-soluble.
Q6. Where do steroid hormone receptors typically reside? ANSWER Inside
the cell (cytoplasm or nucleus).
Q7. How do amino acid–based hormones exert their effects? ANSWER They
bind to receptors on the cell surface and use second messenger systems (e.g.,
cAMP or PIP-calcium).
Q8. What is the cAMP second messenger pathway? ANSWER A hormone
binds a receptor → activates G protein → activates adenylate cyclase →
converts ATP to cAMP → activates protein kinases → cellular response.
Q9. Name two hormones that use the cAMP mechanism. ANSWER
Epinephrine and glucagon.
Q10. What is up-regulation? ANSWER An increase in the number of receptors
on a target cell in response to low hormone levels.
Q11. What is down-regulation? ANSWER A decrease in the number of
receptors in response to persistently high hormone levels.
,Q12. What is a paracrine secretion? ANSWER A chemical that acts on
neighboring cells (local effect).
Q13. What is an autocrine secretion? ANSWER A chemical that acts on the
same cell that produced it.
Q14. What gland is considered the "master gland"? ANSWER The anterior
pituitary (adenohypophysis).
Q15. What structure controls the pituitary gland? ANSWER The
hypothalamus.
Q16. What are the two lobes of the pituitary gland? ANSWER Anterior
pituitary (adenohypophysis) and posterior pituitary (neurohypophysis).
Q17. What hormones are released from the posterior pituitary? ANSWER
ADH (antidiuretic hormone/vasopressin) and oxytocin.
Q18. Where are ADH and oxytocin actually produced? ANSWER In the
hypothalamus; they are stored and released from the posterior pituitary.
Q19. What does ADH do? ANSWER It promotes water reabsorption in the
kidneys, reducing urine output.
Q20. What is the function of oxytocin? ANSWER Stimulates uterine
contractions during labor and milk ejection during breastfeeding.
Q21. What are the six hormones released from the anterior pituitary?
ANSWER GH, TSH, ACTH, FSH, LH, and Prolactin.
Q22. What does TSH stand for and what does it do? ANSWER Thyroid-
stimulating hormone; it stimulates the thyroid gland to release thyroid
hormones.
Q23. What does ACTH do? ANSWER Stimulates the adrenal cortex to secrete
cortisol.
Q24. What does growth hormone (GH) do? ANSWER Stimulates growth of
body tissues, especially bone and muscle; promotes protein synthesis and fat
breakdown.
Q25. What is IGF (Insulin-like Growth Factor)? ANSWER A hormone
released by the liver in response to GH that mediates many of GH's growth-
promoting effects.
, Q26. What disorder results from excess GH in adults? ANSWER Acromegaly.
Q27. What disorder results from GH deficiency in children? ANSWER
Pituitary dwarfism.
Q28. What are the two thyroid hormones? ANSWER T3 (triiodothyronine)
and T4 (thyroxine).
Q29. What mineral is required to make thyroid hormones? ANSWER Iodine.
Q30. What is the primary effect of thyroid hormones? ANSWER Increase
metabolic rate (basal metabolic rate).
Q31. What is hypothyroidism? ANSWER Low thyroid hormone production;
symptoms include fatigue, weight gain, and cold intolerance.
Q32. What is hyperthyroidism? ANSWER Excess thyroid hormone; symptoms
include weight loss, heat intolerance, and rapid heart rate.
Q33. What is a goiter? ANSWER Enlargement of the thyroid gland, often due
to iodine deficiency or excessive TSH stimulation.
Q34. What hormone does the thyroid gland release to lower blood calcium?
ANSWER Calcitonin.
Q35. What do parathyroid glands produce? ANSWER Parathyroid hormone
(PTH).
Q36. What does PTH do to blood calcium levels? ANSWER Raises blood
calcium by stimulating osteoclasts, increasing kidney reabsorption of calcium,
and activating vitamin D.
Q37. What are the two regions of the adrenal gland? ANSWER Adrenal cortex
(outer) and adrenal medulla (inner).
Q38. What hormones does the adrenal medulla secrete? ANSWER
Epinephrine (adrenaline) and norepinephrine (noradrenaline).
Q39. What are the three classes of hormones from the adrenal cortex?
ANSWER Mineralocorticoids, glucocorticoids, and gonadocorticoids
(androgens).
Q40. What is the main mineralocorticoid? ANSWER Aldosterone.
