Free Endocrine System MCQs with Answers

• A. It releases hormones into the bloodstream
• B. It releases enzymes into a body cavity
• C. It sends impulses through peripheral nerves
• D. It produces mucus for a body surface

Explanation: Endocrine glands are ductless glands that release hormones into the blood for transport to target cells.

• A. It is produced by the kidneys and stored in the thyroid
• B. It is produced by the hypothalamus and released by the posterior pituitary
• C. It is produced by the adrenal cortex and released by the pancreas
• D. It is produced by the anterior pituitary and stored in the hypothalamus

Explanation: ADH is synthesized by neurons in the hypothalamus and transported to the posterior pituitary for storage and release.

• A. Raising blood glucose by breaking down glycogen
• B. Increasing blood calcium by stimulating bone breakdown
• C. Lowering blood glucose by promoting cellular uptake
• D. Increasing heart rate by stimulating sympathetic activity

Explanation: Insulin, released by pancreatic beta cells, lowers blood glucose by helping cells take up glucose and by promoting glycogen formation.

• A. The hypothalamus increases thyrotropin-releasing hormone
• B. The anterior pituitary increases thyroid-stimulating hormone
• C. The hypothalamus and pituitary reduce their stimulating hormones
• D. The thyroid gland releases more thyroxine to restore balance

Explanation: High thyroxine suppresses hypothalamic thyrotropin-releasing hormone and pituitary thyroid-stimulating hormone.

• A. Calcitonin
• B. Parathyroid hormone
• C. Aldosterone
• D. Thyroid-stimulating hormone

Explanation: Parathyroid hormone raises blood calcium by acting on bone, kidneys and indirectly the intestine.

• A. Cortisol suppresses immune activity and increases blood glucose
• B. Insulin suppresses immune activity and decreases blood glucose
• C. Thyroxine suppresses immune activity and decreases blood glucose
• D. ADH suppresses immune activity and increases blood glucose

Explanation: Cortisol from the adrenal cortex suppresses inflammatory and immune responses and promotes gluconeogenesis, which can raise blood glucose.

• A. Insulin
• B. ADH
• C. Cortisol
• D. Epinephrine

Explanation: Cortisol is a lipid-soluble steroid hormone that crosses the cell membrane and binds an intracellular receptor, changing gene…

• A. Growth hormone
• B. Antidiuretic hormone
• C. Aldosterone
• D. Calcitonin

Explanation: Growth hormone from the anterior pituitary supports bone and tissue growth, partly through insulin-like growth factor 1.

• A. Excess thyroid hormone secretion
• B. Reduced thyroid hormone secretion
• C. Excess adrenal medulla secretion
• D. Reduced parathyroid hormone secretion

Explanation: Reduced thyroid hormone secretion slows metabolic activity and commonly causes fatigue, cold intolerance, constipation and weight gain.

• A. Give a rapid-acting oral carbohydrate
• B. Administer the scheduled long-acting insulin
• C. Restrict oral fluids until the glucose rises
• D. Encourage the patient to walk to improve alertness

Explanation: A conscious patient with symptomatic hypoglycaemia should receive a rapidly absorbed oral carbohydrate, then have glucose rechecked…

• A. The cell contains a matching hormone receptor
• B. The cell receives a larger blood supply
• C. The cell contains more mitochondria
• D. The cell has a thicker plasma membrane

Explanation: A target cell has a receptor with a shape that matches the hormone, allowing a specific response.

• A. Thyroxine
• B. Aldosterone
• C. Glucagon
• D. Parathyroid hormone

Explanation: Thyroxine, also called T4, increases cellular metabolic activity and supports normal growth and development.

• A. Sodium retention and potassium loss
• B. Sodium loss and potassium retention
• C. Low blood pressure and low blood volume
• D. Reduced water reabsorption in the kidneys

Explanation: Aldosterone promotes sodium reabsorption and potassium excretion in the distal nephron.

• A. Glucagon
• B. Insulin
• C. Somatostatin
• D. Amylase

Explanation: Glucagon is released by pancreatic alpha cells when blood glucose falls and promotes glycogen breakdown and glucose production by the…

• A. Hyperglycaemia and increased infection risk
• B. Hypoglycaemia and increased muscle strength
• C. Severe weight loss and increased skin pigmentation
• D. Low blood pressure and reduced sodium retention

Explanation: Cortisol raises blood glucose and suppresses immune and inflammatory responses, increasing infection risk.

• A. Oxytocin
• B. Prolactin
• C. Follicle-stimulating hormone
• D. Adrenocorticotropic hormone

Explanation: The posterior pituitary releases oxytocin, which stimulates uterine contractions and milk ejection.

• A. Melatonin
• B. Thymosin
• C. Calcitonin
• D. Erythropoietin

Explanation: Melatonin from the pineal gland helps regulate circadian sleep and wake rhythms, especially in response to darkness.

• A. Reduced parathyroid hormone secretion
• B. Increased adrenal medulla secretion
• C. Reduced pancreatic glucagon secretion
• D. Increased thyroid hormone secretion

Explanation: Injury or removal of the parathyroid glands can reduce parathyroid hormone, lowering blood calcium and causing neuromuscular irritability.

• A. Oestrogen
• B. Testosterone
• C. Cortisol
• D. Aldosterone

Explanation: Oestrogen is produced mainly by the ovaries and supports female reproductive development, including breast development and female body fat…

• A. Assess circulation and notify the provider urgently
• B. Encourage ambulation to improve blood pressure
• C. Restrict fluids to reduce adrenal workload
• D. Give the next steroid dose only if fever develops

Explanation: Weakness, dizziness and hypotension after abrupt steroid withdrawal suggest adrenal insufficiency, which can threaten circulation.