Endocrine System Practice Questions

64 multiple-choice questions on Endocrine system for paramedic and EMT students, from Chapter 8 (Anatomy and Physiology). Read each question, pick your answer, then tap Show answer to check it and read the explanation.

64 practice questions

1. Endocrine glands secrete hormones:

   1. A. Only into the lymph
   2. B. Only into the GI tract
   3. C. Through ducts onto a surface
   4. D. Directly into the bloodstream
   Show answer

   Answer: D. Directly into the bloodstream

   Endocrine glands are ductless. Exocrine glands use ducts, like sweat glands or the pancreas releasing digestive enzymes.

2. Which gland is often called the master gland?

   1. A. Adrenal
   2. B. Pineal
   3. C. Pituitary
   4. D. Thyroid
   Show answer

   Answer: C. Pituitary

   The pituitary controls many other glands and is itself regulated by the hypothalamus.

3. Antidiuretic hormone (ADH) acts to:

   1. A. Raise blood glucose via the liver
   2. B. Increase urine output by the kidneys
   3. C. Promote renal water reabsorption
   4. D. Increase heart rate and contractility
   Show answer

   Answer: C. Promote renal water reabsorption

   ADH conserves water. Alcohol suppresses it, which is why drinking makes you urinate more.

4. Oxytocin causes:

   1. A. Water retention by the kidneys
   2. B. Increased basal metabolic rate
   3. C. Uterine contraction and milk letdown
   4. D. Raised blood calcium levels
   Show answer

   Answer: C. Uterine contraction and milk letdown

   Oxytocin is made by the hypothalamus and released from the posterior pituitary.

5. Thyroid hormones primarily regulate:

   1. A. Sodium balance
   2. B. Sleep cycles
   3. C. Metabolic rate
   4. D. Blood calcium
   Show answer

   Answer: C. Metabolic rate

   T3 and T4 set the metabolic rate. Excess causes tachycardia and heat intolerance; too little causes a slow, cold state.

6. Parathyroid hormone:

   1. A. Raises blood calcium
   2. B. Stimulates the thyroid
   3. C. Lowers blood glucose
   4. D. Lowers blood calcium
   Show answer

   Answer: A. Raises blood calcium

   PTH raises serum calcium. Calcitonin from the thyroid lowers it.

7. The thymus gland is important for:

   1. A. Maturation of T lymphocytes
   2. B. Producing bile for digestion
   3. C. Regulating the sleep-wake cycle
   4. D. Secreting insulin into the blood
   Show answer

   Answer: A. Maturation of T lymphocytes

   The thymus is most active in childhood and helps develop immunity.

8. The adrenal medulla secretes:

   1. A. Thyroxine and calcitonin
   2. B. Epinephrine and norepinephrine
   3. C. Insulin and glucagon
   4. D. Cortisol and other glucocorticoids
   Show answer

   Answer: B. Epinephrine and norepinephrine

   The medulla makes catecholamines for fight or flight. The cortex makes steroids.

9. Cortisol is released by the:

   1. A. Adrenal cortex; raises blood glucose
   2. B. Pancreas; stores glucose as glycogen
   3. C. Adrenal medulla; lowers blood glucose
   4. D. Thyroid; raises metabolic rate
   Show answer

   Answer: A. Adrenal cortex; raises blood glucose

   Cortisol is the stress hormone. Chronic excess causes Cushing syndrome; too little causes adrenal insufficiency. It also suppresses inflammation.

10. Aldosterone causes the kidneys to:

    1. A. Excrete free water and calcium
    2. B. Retain potassium and excrete sodium
    3. C. Retain sodium, excrete potassium
    4. D. Excrete sodium and retain water
    Show answer

    Answer: C. Retain sodium, excrete potassium

    Water follows the retained sodium, which raises blood volume and blood pressure.

11. Which hormone lowers blood glucose, and where is it made?

    1. A. Epinephrine, adrenal medulla
    2. B. Cortisol, adrenal cortex
    3. C. Glucagon, alpha cells of the pancreas
    4. D. Insulin, beta cells of the pancreas
    Show answer

    Answer: D. Insulin, beta cells of the pancreas

    Insulin moves glucose into the cells. It is the only hormone that lowers blood glucose.

12. Glucagon raises blood glucose mainly by:

    1. A. Blocking insulin receptors on cells
    2. B. Increasing glucose excretion
    3. C. Moving glucose into the cells
    4. D. Triggering liver glycogenolysis
    Show answer

    Answer: D. Triggering liver glycogenolysis

    Glucagon triggers glycogenolysis. That is why IM glucagon works for hypoglycemia.

13. The pineal gland secretes:

    1. A. Thymosin
    2. B. Oxytocin
    3. C. Prolactin
    4. D. Melatonin
    Show answer

    Answer: D. Melatonin

    Melatonin regulates the sleep-wake cycle.

14. Hormones are best described as:

    1. A. Electrical impulses along nerves
    2. B. Chemical messengers carried in blood
    3. C. Enzymes that speed reactions
    4. D. Structural proteins in tissue
    Show answer

    Answer: B. Chemical messengers carried in blood

    They act only where receptors exist. Hormones act on target cells.

15. Compared with the nervous system, the endocrine system generally produces effects that are:

    1. A. Faster and longer lasting
    2. B. Identical in onset and duration
    3. C. Faster in onset and briefer
    4. D. Slower in onset, longer lasting
    Show answer

    Answer: D. Slower in onset, longer lasting

    Both systems work together to maintain homeostasis.

16. A target cell responds to a hormone because it:

    1. A. Has receptors for that hormone
    2. B. Has an especially rich blood supply
    3. C. Produces that same hormone
    4. D. Is located near the gland
    Show answer

    Answer: A. Has receptors for that hormone

    Cells without receptors ignore the hormone.

17. Most hormone secretion is regulated by:

    1. A. Positive feedback
    2. B. Negative feedback
    3. C. Random release
    4. D. Nervous input only
    Show answer

    Answer: B. Negative feedback

    Rising hormone levels shut off further release.

18. The anterior pituitary secretes:

    1. A. Aldosterone, cortisol, and DHEA
    2. B. Insulin, glucagon, and somatostatin
    3. C. ADH, oxytocin, and melatonin
    4. D. GH, TSH, ACTH, and prolactin
    Show answer

    Answer: D. GH, TSH, ACTH, and prolactin

    The hypothalamus controls it through releasing hormones. The anterior pituitary secretes growth hormone, TSH, ACTH, FSH, LH, and prolactin.

19. The posterior pituitary stores and releases:

    1. A. ADH and oxytocin
    2. B. Cortisol and aldosterone
    3. C. TSH and thyroid hormone
    4. D. Growth hormone and prolactin
    Show answer

    Answer: A. ADH and oxytocin

    It is an extension of the hypothalamus. Both are made in the hypothalamus.

20. Growth hormone acts to:

    1. A. Increase urine production
    2. B. Lower blood glucose levels
    3. C. Stimulate bone and tissue growth
    4. D. Promote renal sodium retention
    Show answer

    Answer: C. Stimulate bone and tissue growth

    Excess in adults causes acromegaly. It also influences metabolism.

21. Thyroid-stimulating hormone acts on the:

    1. A. Pancreatic islets
    2. B. Adrenal cortex
    3. C. Ovaries and testes
    4. D. Thyroid gland
    Show answer

    Answer: D. Thyroid gland

    It comes from the anterior pituitary. TSH prompts the thyroid to release T3 and T4.

22. Adrenocorticotropic hormone stimulates the:

    1. A. Pancreatic islets
    2. B. Posterior pituitary
    3. C. Thyroid gland
    4. D. Adrenal cortex
    Show answer

    Answer: D. Adrenal cortex

    It is part of the stress response axis. ACTH prompts the adrenal cortex to release cortisol.

23. The thyroid gland is located:

    1. A. In the anterior neck
    2. B. Behind the sternum
    3. C. In the upper abdomen
    4. D. Above the kidneys
    Show answer

    Answer: A. In the anterior neck

    It wraps around the trachea. It sits below the larynx.

24. Thyroid hormone requires which element?

    1. A. Iodine
    2. B. Calcium
    3. C. Iron
    4. D. Zinc
    Show answer

    Answer: A. Iodine

    Deficiency can cause goiter.

25. Calcitonin acts to:

    1. A. Raise blood glucose
    2. B. Raise blood calcium
    3. C. Promote sodium retention
    4. D. Lower blood calcium
    Show answer

    Answer: D. Lower blood calcium

    It opposes parathyroid hormone. It moves calcium into bone.

26. Parathyroid hormone raises blood calcium by:

    1. A. Depositing calcium into bone
    2. B. Stimulating calcitonin release
    3. C. Blocking vitamin D activation
    4. D. Releasing calcium from bone
    Show answer

    Answer: D. Releasing calcium from bone

    Four small glands sit behind the thyroid. PTH also increases intestinal absorption and reduces renal calcium loss.

27. Hypocalcemia produces:

    1. A. Muscle twitching and spasm
    2. B. Bradycardia and hypertension
    3. C. Flaccid muscle weakness
    4. D. Polyuria and kidney stones
    Show answer

    Answer: A. Muscle twitching and spasm

    Severe cases cause tetany and dysrhythmias. Tingling is also common.

28. The adrenal glands sit:

    1. A. On top of each kidney
    2. B. Deep in the pelvis
    3. C. Behind the sternum
    4. D. Beside the thyroid gland
    Show answer

    Answer: A. On top of each kidney

    Each has a cortex and a medulla.

29. The adrenal cortex secretes:

    1. A. Epinephrine and norepinephrine
    2. B. Insulin and somatostatin
    3. C. Thyroxine and triiodothyronine
    4. D. Cortisol, aldosterone, and androgens
    Show answer

    Answer: D. Cortisol, aldosterone, and androgens

    These are steroid hormones.

30. Cortisol's effects include:

    1. A. Lowering blood glucose and fat stores
    2. B. Raising glucose and suppressing inflammation
    3. C. Slowing heart rate and conduction
    4. D. Retaining potassium and excreting sodium
    Show answer

    Answer: B. Raising glucose and suppressing inflammation

    Long-term steroid users cannot mount a stress response normally. Cortisol also supports the stress response.

31. Aldosterone acts on the:

    1. A. Alveolar capillaries
    2. B. Pancreatic islets
    3. C. Liver hepatocytes
    4. D. Renal tubules
    Show answer

    Answer: D. Renal tubules

    It raises blood volume and pressure. It makes the kidney tubules retain sodium and water and excrete potassium.

32. The renin-angiotensin-aldosterone system is triggered by:

    1. A. High sodium intake
    2. B. Elevated blood pressure
    3. C. Reduced renal perfusion
    4. D. Rising blood glucose
    Show answer

    Answer: C. Reduced renal perfusion

    It is a key compensation in shock.

33. Angiotensin II acts to:

    1. A. Increase sodium and water excretion
    2. B. Constrict vessels and release aldosterone
    3. C. Dilate vessels and lower blood pressure
    4. D. Inhibit ADH and aldosterone release
    Show answer

    Answer: B. Constrict vessels and release aldosterone

    ACE inhibitors block its formation.

34. The islets of Langerhans are located in the:

    1. A. Liver
    2. B. Thyroid
    3. C. Adrenal gland
    4. D. Pancreas
    Show answer

    Answer: D. Pancreas

    They contain alpha, beta, and delta cells.

35. Beta cells of the pancreas produce:

    1. A. Glucagon
    2. B. Somatostatin
    3. C. Cortisol
    4. D. Insulin
    Show answer

    Answer: D. Insulin

    Alpha cells produce glucagon.

36. Insulin allows glucose to:

    1. A. Enter cells for fuel
    2. B. Be excreted in urine
    3. C. Stay in the bloodstream
    4. D. Be converted to protein
    Show answer

    Answer: A. Enter cells for fuel

    Without it, cells starve despite high blood glucose.

37. Type 1 diabetes results from:

    1. A. Adrenal cortex failure
    2. B. Excess glucagon secretion
    3. C. Autoimmune beta cell loss
    4. D. Peripheral insulin resistance
    Show answer

    Answer: C. Autoimmune beta cell loss

    These patients require insulin. Little or no insulin is produced.

38. Type 2 diabetes involves primarily:

    1. A. Thyroid hormone deficiency
    2. B. Insulin resistance
    3. C. Excess glucagon release
    4. D. Absent insulin production
    Show answer

    Answer: B. Insulin resistance

    It is strongly associated with obesity and inactivity. There is also relative insulin deficiency.

39. Twenty minutes after IM glucagon, an unresponsive hypoglycemic patient wakes and can swallow. What is the best next step?

    1. A. Give oral carbohydrates and food
    2. B. Leave, since the glucose is now normal
    3. C. Give a second glucagon dose routinely
    4. D. Keep him NPO for 24 hours
    Show answer

    Answer: A. Give oral carbohydrates and food

    Glucagon works by breaking down liver glycogen. Its effect is short and it uses up glycogen stores, so glucose can fall again. Once the patient can swallow safely, oral carbohydrates and a meal maintain the level. Routine repeat doses are not the plan, and withholding food invites a relapse.

40. Somatostatin functions to:

    1. A. Inhibit insulin and glucagon
    2. B. Raise blood glucose directly
    3. C. Promote sodium retention
    4. D. Stimulate growth hormone release
    Show answer

    Answer: A. Inhibit insulin and glucagon

    It helps modulate the other pancreatic hormones.

41. Epinephrine released from the adrenal medulla produces:

    1. A. Increased gut motility and digestion
    2. B. Vasodilation and falling blood pressure
    3. C. Tachycardia, bronchodilation, hyperglycemia
    4. D. Bradycardia and bronchoconstriction
    Show answer

    Answer: C. Tachycardia, bronchodilation, hyperglycemia

    It prepares the body for exertion. It also increases contractility.

42. The thymus gland is most active during:

    1. A. Pregnancy
    2. B. Old age
    3. C. Middle age
    4. D. Childhood
    Show answer

    Answer: D. Childhood

    It shrinks with age. It supports T lymphocyte development.

43. A night-shift paramedic struggles to sleep in daylight. Which gland's hormone, suppressed by light, is most involved?

    1. A. Thyroid gland (thyroxine)
    2. B. Adrenal medulla (epinephrine)
    3. C. Pineal gland (melatonin)
    4. D. Posterior pituitary (ADH)
    Show answer

    Answer: C. Pineal gland (melatonin)

    The pineal gland releases melatonin in darkness to promote sleep, and light suppresses it, which disrupts sleep for shift workers. Thyroxine sets metabolic rate, epinephrine drives the stress response, and ADH controls water reabsorption.

44. The gonads secrete:

    1. A. Insulin and glucagon
    2. B. Testosterone and estrogen
    3. C. Cortisol and aldosterone
    4. D. Thyroxine and calcitonin
    Show answer

    Answer: B. Testosterone and estrogen

    They are influenced by pituitary FSH and LH. Progesterone is another gonadal sex hormone.

45. After delivery, the mother's uterus is boggy and she is bleeding. Putting the baby to the breast helps because suckling releases:

    1. A. Prolactin, which contracts the uterus
    2. B. Progesterone, which relaxes the uterus
    3. C. ADH, which raises blood volume
    4. D. Oxytocin, which contracts the uterus
    Show answer

    Answer: D. Oxytocin, which contracts the uterus

    Nipple stimulation triggers oxytocin release from the posterior pituitary, which contracts the uterine muscle and clamps the bleeding vessels. Fundal massage does the same mechanically. Prolactin drives milk production, not contraction. Progesterone relaxes the uterus, and ADH acts on the kidneys.

46. Antidiuretic hormone is released in response to:

    1. A. High blood glucose
    2. B. Low serum potassium
    3. C. Dehydration
    4. D. Overhydration
    Show answer

    Answer: C. Dehydration

    It concentrates urine. Rising blood osmolarity is the trigger.

47. Diabetes insipidus results from:

    1. A. Insufficient ADH effect
    2. B. Excess insulin secretion
    3. C. Excess cortisol secretion
    4. D. Insulin resistance
    Show answer

    Answer: A. Insufficient ADH effect

    It is unrelated to blood glucose. It produces large volumes of dilute urine.

48. Hyperthyroidism typically produces:

    1. A. Constipation and dry skin
    2. B. Weight gain and cold intolerance
    3. C. Weight loss and heat intolerance
    4. D. Bradycardia and fatigue
    Show answer

    Answer: C. Weight loss and heat intolerance

    Thyroid storm is the life-threatening form. Tachycardia and anxiety are also typical.

49. Hypothyroidism typically produces:

    1. A. Weight loss and tachycardia
    2. B. Heat intolerance and sweating
    3. C. Weight gain and cold intolerance
    4. D. Tremor, anxiety, and insomnia
    Show answer

    Answer: C. Weight gain and cold intolerance

    Myxedema coma is the severe form. Fatigue and slowed mentation are also typical.

50. Cushing syndrome results from:

    1. A. Insufficient cortisol
    2. B. Low aldosterone
    3. C. Excess cortisol
    4. D. Excess insulin
    Show answer

    Answer: C. Excess cortisol

    It may be caused by long-term steroid therapy. Excess cortisol produces weight gain, hypertension, and hyperglycemia.

51. Addison disease results from:

    1. A. Adrenal insufficiency
    2. B. Excess insulin secretion
    3. C. Excess thyroid hormone
    4. D. Excess cortisol
    Show answer

    Answer: A. Adrenal insufficiency

    Patients may present with hypotension, weakness, and hypoglycemia. Both cortisol and aldosterone are low.

52. Stress activates which hormonal axis?

    1. A. Hypothalamic-pituitary-adrenal
    2. B. Hypothalamic-pituitary-gonadal
    3. C. Hypothalamic-pituitary-thyroid only
    4. D. Pancreatic islet axis
    Show answer

    Answer: A. Hypothalamic-pituitary-adrenal

    Catecholamines are released simultaneously. The HPA axis raises cortisol.

53. A patient on long-term corticosteroids who becomes ill may:

    1. A. Overproduce cortisol from adrenal rebound
    2. B. Fail to mount a stress response
    3. C. Release extra ACTH to compensate
    4. D. Need less steroid medication
    Show answer

    Answer: B. Fail to mount a stress response

    Adrenal suppression is the reason. They may require supplemental steroids. Long-term steroids suppress the hypothalamic-pituitary-adrenal axis, so ACTH and the patient's own cortisol stay low during illness instead of rising.

54. For hyperkalemia, the ED gives IV insulin together with dextrose. Why is dextrose given with the insulin?

    1. A. Dextrose makes the insulin work faster on potassium
    2. B. Dextrose by itself lowers potassium more than insulin
    3. C. Insulin given IV raises the blood glucose level
    4. D. Insulin moves glucose into cells and can cause hypoglycemia
    Show answer

    Answer: D. Insulin moves glucose into cells and can cause hypoglycemia

    Insulin shifts potassium into cells, but it also drives glucose into cells and lowers blood sugar, so dextrose is given to prevent hypoglycemia. Dextrose alone does little to potassium unless it triggers insulin release. Insulin lowers glucose; it does not raise it.

55. Which hormones raise blood glucose?

    1. A. Insulin and somatostatin
    2. B. Glucagon, cortisol, and epinephrine
    3. C. Aldosterone and antidiuretic hormone
    4. D. Calcitonin and parathyroid hormone
    Show answer

    Answer: B. Glucagon, cortisol, and epinephrine

    Multiple pathways protect against hypoglycemia. Growth hormone also raises glucose.

56. Hormone receptors may be located:

    1. A. Only inside the cell nucleus
    2. B. Free in the blood plasma
    3. C. On the membrane or inside the cell
    4. D. Only on the cell membrane surface
    Show answer

    Answer: C. On the membrane or inside the cell

    Steroid hormones typically act inside the cell.

57. The hypothalamus controls the pituitary through:

    1. A. Hormones secreted into the CSF
    2. B. Direct nerve fibers to both lobes
    3. C. Portal hormones and nerve fibers
    4. D. Changes in local blood pressure
    Show answer

    Answer: C. Portal hormones and nerve fibers

    It bridges the nervous and endocrine systems. Releasing and inhibiting hormones travel in a portal circulation to the anterior lobe; nerve fibers reach the posterior lobe.

58. A tumor of the adrenal medulla producing excess catecholamines is called a:

    1. A. Pheochromocytoma
    2. B. Insulinoma
    3. C. Adenoma of the thyroid
    4. D. Goiter
    Show answer

    Answer: A. Pheochromocytoma

    It causes episodic severe hypertension.

59. Endocrine emergencies commonly present with:

    1. A. Altered mentation and abnormal vitals
    2. B. An isolated rash or skin change
    3. C. Localized pain without systemic signs
    4. D. No signs until organ failure
    Show answer

    Answer: A. Altered mentation and abnormal vitals

    Always check the glucose. Glucose abnormalities are common.

60. Insulin secretion normally increases:

    1. A. During exercise only
    2. B. After a meal
    3. C. During fasting
    4. D. At night only
    Show answer

    Answer: B. After a meal

    Glucagon rises between meals. Rising blood glucose triggers it.

61. The main stimulus for parathyroid hormone release is:

    1. A. High blood calcium
    2. B. Low sodium
    3. C. Low blood calcium
    4. D. High glucose
    Show answer

    Answer: C. Low blood calcium

    Feedback keeps calcium within a narrow range.

62. Excess growth hormone in a child produces:

    1. A. Acromegaly
    2. B. Gigantism
    3. C. Cretinism
    4. D. Dwarfism
    Show answer

    Answer: B. Gigantism

    In adults it causes acromegaly. Cretinism is the stunted growth and intellectual disability of untreated congenital hypothyroidism, not growth hormone excess.

63. Which statement about hormone half-life is accurate?

    1. A. Peptide hormones outlast steroid hormones
    2. B. Protein binding shortens hormone half-life
    3. C. Hormones vary widely in duration
    4. D. Liver failure shortens most half-lives
    Show answer

    Answer: C. Hormones vary widely in duration

    Catecholamines act in seconds; thyroid hormone lasts days. Peptide hormones are usually cleared within minutes, while protein-bound steroid and thyroid hormones last longer. Binding to carrier proteins protects hormones and lengthens half-life, and liver failure slows hormone breakdown, prolonging it.

64. The endocrine system maintains homeostasis by:

    1. A. Direct nerve control of every organ
    2. B. Hormonal control of metabolism and fluids
    3. C. Coordinated skeletal muscle contraction
    4. D. Filtering the blood through glands
    Show answer

    Answer: B. Hormonal control of metabolism and fluids

    Most systems are under some hormonal influence. Hormones also adjust growth and the stress response.