Endocrine Anatomy and Physiology Practice Questions

25 multiple-choice questions on Endocrine anatomy and physiology for paramedic and EMT students, from Chapter 24 (Endocrine Emergencies). Read each question, pick your answer, then tap Show answer to check it and read the explanation.

25 practice questions

1. A trauma patient with no history of diabetes has a glucose of 210 mg/dL. The most likely reason is:

   1. A. New type 1 diabetes from the crash
   2. B. Stress hormones raising glucose
   3. C. A broken glucose meter or strip
   4. D. Too much oral glucose given by EMTs
   Show answer

   Answer: B. Stress hormones raising glucose

   Epinephrine, cortisol, glucagon, and growth hormone released during major stress raise blood glucose (stress hyperglycemia). It is common after trauma, MI, and stroke and is associated with worse outcomes, but it is not new diabetes.

2. A 28-year-old woman has stopped having periods and has milky nipple discharge without being pregnant. A likely cause is:

   1. A. A prolactin-secreting tumor
   2. B. An overactive thyroid nodule
   3. C. A tumor of the adrenal medulla
   4. D. Low blood calcium levels
   Show answer

   Answer: A. A prolactin-secreting tumor

   Prolactinomas are the most common hormone-secreting pituitary tumors. Excess prolactin suppresses ovulation and causes galactorrhea. Pregnancy must be excluded first.

3. A large pituitary tumor pressing on the optic chiasm typically causes:

   1. A. Sudden total blindness in one eye
   2. B. Double vision only when reading
   3. C. Loss of side vision in both eyes
   4. D. Red, painful eyes with discharge
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   Answer: C. Loss of side vision in both eyes

   The optic chiasm lies just above the pituitary, and the crossing nasal fibers carry the outer (temporal) visual fields, so compression causes bitemporal field loss that patients may notice as bumping into things.

4. After several days without food, the brain can meet part of its energy needs by using:

   1. A. Fatty acids taken up directly
   2. B. Glycogen in neurons
   3. C. Cholesterol from the blood
   4. D. Ketones made from fat
   Show answer

   Answer: D. Ketones made from fat

   During prolonged fasting, the liver turns fatty acids into ketones, which the brain can use for a large share of its fuel, sparing protein. This is why mild ketosis occurs in starvation without diabetes. Fatty acids cannot reach the brain in useful amounts, neurons store very little glycogen, and cholesterol is not burned for fuel.

5. Insulin is given by injection, pump, or inhalation rather than as a pill mainly because it:

   1. A. Is absorbed too fast by the gut
   2. B. Works poorly at body temperature
   3. C. Irritates the stomach lining
   4. D. Is a protein digestion destroys
   Show answer

   Answer: D. Is a protein digestion destroys

   Insulin is a peptide hormone that stomach acid and digestive enzymes break down, so it must bypass the gut. Oral diabetes medications are different drugs that work by other mechanisms. Insulin is not absorbed too quickly, it works normally at body temperature, and it does not irritate the stomach.

6. Young children become hypoglycemic faster than adults during a vomiting illness mainly because they:

   1. A. Make too much insulin when ill
   2. B. Absorb sugar far too quickly
   3. C. Have small glycogen stores
   4. D. Lose glucose through their skin
   Show answer

   Answer: C. Have small glycogen stores

   Children have high metabolic rates and limited liver glycogen, so fasting during illness can quickly lower their glucose. Check glucose in any lethargic, vomiting child.

7. A person with diabetes has the highest glucose of the day before breakfast despite no bedtime snack. A common reason is:

   1. A. Early-morning hormone surges
   2. B. Insulin works better at night
   3. C. A rebound from a bedtime snack
   4. D. Overnight dehydration of the blood
   Show answer

   Answer: A. Early-morning hormone surges

   In the dawn phenomenon, growth hormone and cortisol released in the early morning raise glucose. It is a normal pattern that becomes exaggerated in diabetes. There was no snack to rebound from, and overnight fluid shifts do not explain the rise.

8. Fingerstick glucose readings are least reliable in a patient who has:

   1. A. A normal blood pressure
   2. B. Poor perfusion from shock
   3. C. Warm, pink fingertips
   4. D. Clean, dry hands after washing
   Show answer

   Answer: B. Poor perfusion from shock

   In shock or severe peripheral vasoconstriction, capillary samples may not reflect blood glucose, and the FDA cautions against relying on them in critically ill patients. Use a venous sample when possible.

9. Why does the brain depend so heavily on a steady glucose supply?

   1. A. It burns only fat for energy
   2. B. It needs insulin to use glucose
   3. C. It stores glycogen for days
   4. D. It cannot store much glucose
   Show answer

   Answer: D. It cannot store much glucose

   The brain uses glucose as its main fuel and has almost no reserve, so hypoglycemia quickly causes confusion, seizures, and coma. Brain cells do not need insulin to take up glucose.

10. Excess thyroid hormone causes tachycardia and tremor partly because it makes tissues more sensitive to:

    1. A. Catecholamines
    2. B. Insulin
    3. C. Vitamin D
    4. D. Acetylcholine release
    Show answer

    Answer: A. Catecholamines

    Thyroid hormone increases beta-adrenergic receptor responsiveness, so hyperthyroid patients look 'adrenergic.' That is why beta blockers relieve many symptoms of thyrotoxicosis.

11. After a nuclear power plant accident, potassium iodide tablets are given to protect the:

    1. A. Lungs from radioactive dust
    2. B. Skin from radiation burns
    3. C. Thyroid from radioactive iodine
    4. D. Bone marrow from all gamma rays
    Show answer

    Answer: C. Thyroid from radioactive iodine

    Potassium iodide floods the thyroid with stable iodine so it absorbs less radioactive iodine. It does not protect other organs or against external radiation.

12. Besides ADH, which hormone strongly triggers thirst when blood volume falls?

    1. A. Melatonin
    2. B. Angiotensin II
    3. C. Calcitonin
    4. D. Thyroid hormone
    Show answer

    Answer: B. Angiotensin II

    Low blood volume activates the renin-angiotensin system; angiotensin II acts on the brain to stimulate thirst and on the adrenal cortex to release aldosterone. Melatonin and calcitonin have no role in thirst.

13. Accidental removal of the parathyroid glands during thyroid surgery may cause:

    1. A. Hypocalcemia with tetany
    2. B. Hyperglycemia with ketosis
    3. C. Hypernatremia with seizures
    4. D. Hypercalcemia with stones
    Show answer

    Answer: A. Hypocalcemia with tetany

    Without PTH, calcium falls, causing tingling around the mouth, muscle cramps, and carpopedal spasm.

14. Why does missing one dose of levothyroxine rarely cause immediate symptoms?

    1. A. Its half-life is about 2 hours
    2. B. The liver makes extra T4 to cover it
    3. C. The kidneys stop clearing it
    4. D. Its half-life is about a week
    Show answer

    Answer: D. Its half-life is about a week

    Levothyroxine (T4) has a half-life of about 7 days, so levels fall slowly. Symptoms of hypothyroidism appear over weeks after stopping, not hours. A 2-hour half-life would make missed doses felt within the day, the liver does not make T4, and the kidneys do not stop clearing it.

15. Injecting insulin into the same spot repeatedly causes fatty lumps under the skin that:

    1. A. Signal an allergy to insulin
    2. B. Mean the needle hit muscle
    3. C. Absorb insulin unpredictably
    4. D. Turn into abscesses over time
    Show answer

    Answer: C. Absorb insulin unpredictably

    Lipohypertrophy from repeated injections at one site causes erratic insulin absorption and unexplained highs and lows. Rotating sites prevents it. The lumps are a local effect of insulin on fat, not an allergy, a sign of muscle injection, or an infection.

16. A patient lacking cortisol stays hypotensive despite fluids partly because, without cortisol, blood vessels:

    1. A. Constrict much too strongly
    2. B. Respond poorly to catecholamines
    3. C. Fill up with extra red blood cells
    4. D. Make too much aldosterone
    Show answer

    Answer: B. Respond poorly to catecholamines

    Cortisol has a permissive effect on vascular tone: without it, vessels respond weakly to epinephrine and norepinephrine, causing refractory shock. Giving hydrocortisone restores vasopressor responsiveness.

17. In healthy people, the blood cortisol level is normally highest:

    1. A. Right after dinner
    2. B. In the middle of the night
    3. C. Late in the afternoon
    4. D. In the early morning
    Show answer

    Answer: D. In the early morning

    Cortisol follows a daily (circadian) rhythm, peaking shortly after waking and falling to its lowest around midnight. This is why steroid replacement doses are usually larger in the morning.

18. ADH release rises mainly in response to:

    1. A. High blood glucose after meals
    2. B. Bright light early in the morning
    3. C. Concentrated blood or low volume
    4. D. A full stomach after eating
    Show answer

    Answer: C. Concentrated blood or low volume

    Osmoreceptors in the hypothalamus trigger ADH release when blood becomes concentrated, and stretch receptors trigger it when volume or pressure falls. Nausea, pain, and some drugs also stimulate ADH.

19. When a failing thyroid makes too little hormone (primary hypothyroidism), the TSH level is usually:

    1. A. Low
    2. B. High
    3. C. Normal
    4. D. Undetectable
    Show answer

    Answer: B. High

    Through negative feedback, the pituitary releases more TSH to push the failing thyroid. A high TSH with low T4 is the typical lab pattern of primary hypothyroidism.

20. Cushing disease, as opposed to the broader term Cushing syndrome, refers to cortisol excess caused by:

    1. A. A pituitary tumor making ACTH
    2. B. Long-term prednisone use
    3. C. An adrenal tumor making cortisol
    4. D. A lung tumor making ACTH
    Show answer

    Answer: A. A pituitary tumor making ACTH

    Cushing syndrome is any cortisol excess, most often from steroid medication. Cushing disease is the specific form caused by an ACTH-secreting pituitary adenoma. An adrenal tumor making cortisol and a lung tumor making ACTH both cause Cushing syndrome, but not Cushing disease.

21. Night-shift workers often sleep poorly during the day partly because daylight:

    1. A. Raises insulin release
    2. B. Suppresses melatonin release
    3. C. Blocks thyroid hormone release
    4. D. Lowers cortisol at noon
    Show answer

    Answer: B. Suppresses melatonin release

    The pineal gland releases melatonin in darkness, and light exposure suppresses it, disrupting daytime sleep. Dark, cool rooms and consistent schedules help shift workers sleep.

22. Insulin left in a hot vehicle for a long time may:

    1. A. Become a stronger dose
    2. B. Turn into glucagon
    3. C. Lose its potency
    4. D. Cause an allergy
    Show answer

    Answer: C. Lose its potency

    Insulin is a protein that degrades with heat or freezing, so overheated insulin may not lower glucose as expected. Ask about storage when a patient's glucose is unexpectedly high.

23. Liver glycogen stores can maintain blood glucose during fasting for roughly:

    1. A. About 10 minutes
    2. B. About 2 weeks
    3. C. About 3 months
    4. D. About a day
    Show answer

    Answer: D. About a day

    Liver glycogen is largely used up within about 24 hours of fasting, after which the body relies on making new glucose and on ketones. Heavy drinkers and malnourished patients have even less in reserve.

24. A type 1 diabetic checks her blood ketones at home during an illness and gets a high reading. This means she:

    1. A. Is at risk of DKA; seek care
    2. B. Has normal levels for an illness
    3. C. Needs to stop her insulin now
    4. D. Should exercise to burn them off
    Show answer

    Answer: A. Is at risk of DKA; seek care

    Sick-day rules advise checking ketones; moderate to high ketones signal insulin deficiency and risk of DKA. Insulin should not be stopped, and exercise with high ketones can worsen ketosis.

25. Epinephrine released during hypoglycemia causes which signs?

    1. A. Sweating, tremor, tachycardia
    2. B. Warm, dry, and flushed skin
    3. C. Bradycardia and low blood pressure
    4. D. Deep, slow breathing
    Show answer

    Answer: A. Sweating, tremor, tachycardia

    The adrenergic response to low glucose causes diaphoresis, shaking, anxiety, and a fast pulse. Beta blockers can blunt these warning signs.