Biology - The Endocrine System - Other Hormones - MCAT Practice Questions

Which hormone is responsible for regulating blood calcium levels by promoting calcium reabsorption in the kidneys?

A. Parathyroid hormone (PTH)
B. Calcitonin
C. Aldosterone
D. Insulin

Calcitonin is produced by which cells and has what primary function?

A. Chief cells of parathyroid; raises blood calcium
B. C cells of the thyroid; lowers blood calcium
C. Beta cells of pancreas; lowers blood glucose
D. Zona glomerulosa; regulates sodium

Which hormone is produced by the pineal gland and regulates circadian rhythms?

A. Serotonin
B. Dopamine
C. Melatonin
D. Norepinephrine

Erythropoietin (EPO) is primarily produced by which organ and stimulates what process?

A. Liver; protein synthesis
B. Bone marrow; white blood cell production
C. Spleen; platelet production
D. Kidneys; red blood cell production

Which pancreatic hormone opposes the action of insulin by raising blood glucose levels?

A. Somatostatin
B. Glucagon
C. Amylin
D. Pancreatic polypeptide

Leptin is produced by which tissue and has what primary function in metabolism?

A. Adipose tissue; suppresses appetite
B. Stomach; stimulates hunger
C. Liver; promotes glucose storage
D. Muscle; increases protein synthesis

Ghrelin is known as the "hunger hormone" and is primarily produced by which organ?

A. Hypothalamus
B. Pancreas
C. Stomach
D. Small intestine

Which hormone is produced by the heart and helps regulate blood pressure and fluid balance?

A. Renin
B. Angiotensin II
C. Aldosterone
D. Atrial natriuretic peptide (ANP)

Gastrin is produced by G cells in the stomach and primarily stimulates the secretion of:

A. Pepsinogen
B. Hydrochloric acid
C. Mucus
D. Bicarbonate

Which hormone produced by the small intestine stimulates the release of digestive enzymes from the pancreas?

A. Cholecystokinin (CCK)
B. Secretin
C. Gastric inhibitory peptide (GIP)
D. Motilin

Secretin is released in response to acidic chyme entering the duodenum and primarily stimulates:

A. Gastric acid production
B. Bile production by the liver
C. Bicarbonate secretion from the pancreas
D. Pepsinogen activation

Which thyroid hormone is more biologically active and has a shorter half-life?

A. T4 (thyroxine)
B. T3 (triiodothyronine)
C. Reverse T3
D. Thyroglobulin

Cortisol is classified as which type of hormone and is produced in which zone of the adrenal cortex?

A. Mineralocorticoid; zona glomerulosa
B. Androgen; zona reticularis
C. Catecholamine; adrenal medulla
D. Glucocorticoid; zona fasciculata

Which hormone is produced by the corpus luteum and helps maintain pregnancy in early stages?

A. Progesterone
B. Estrogen
C. LH (luteinizing hormone)
D. hCG (human chorionic gonadotropin)

Testosterone is primarily produced by which cells in the testes?

A. Sertoli cells
B. Spermatogonia
C. Leydig cells
D. Granulosa cells

Which hormone produced by the placenta is detected in pregnancy tests?

A. Progesterone
B. Estrogen
C. Prolactin
D. hCG (human chorionic gonadotropin)

Inhibin is produced by which cells and has what effect on FSH secretion?

A. Leydig cells; stimulates FSH
B. Sertoli/granulosa cells; inhibits FSH
C. Theca cells; stimulates LH
D. Corpus luteum; inhibits LH

Which hormone stimulates milk production in mammary glands?

A. Prolactin
B. Oxytocin
C. Estrogen
D. Progesterone

Vitamin D3 (calcitriol) functions as a hormone and primarily regulates the absorption of which minerals?

A. Sodium and potassium
B. Iron and zinc
C. Calcium and phosphate
D. Magnesium and sulfate

Which enzyme converts angiotensinogen to angiotensin I in the renin-angiotensin-aldosterone system?

A. ACE (angiotensin-converting enzyme)
B. Aldosterone synthase
C. Angiotensinase
D. Renin