Biology · General Awareness

Human Endocrine System

1,395 Questions

The human endocrine system comprises glands that secrete hormones to regulate bodily functions like metabolism, growth, and reproduction. Competitive exams frequently test the specific roles of hormones such as adrenaline, insulin, and progesterone. Use these questions to master the locations and functions of different hormones.

Hormone functionsIslets of LangerhansFight or flight responseBlood pressure regulationFemale sex hormonesWater soluble hormones

Human Endocrine System Questions

Multiple choice

Which of the following statements is incorrect?

  1. Insulin is secreted by the by β-cells islets of Langerhans.

  2. Human insulin is a polypeptide of 51 amino acids arranged in a single chain.

  3. Banting and Best isolated insulin from a dog’s pancreas.

  4. Insulin regulates carbohydrate metabolism.

  5. Humulin is synthetic human insulin.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Human insulin is a polypeptide of 51 amino acids arranged in two chains (A and B) bearing 21 and 30 amino acids, respectively.

Multiple choice

Which of the following statements regarding adrenocorticotropic hormone is TRUE?

  1. It is produced and secreted by the hyothalamus gland.

  2. It is a single polypeptide containing 39 amino acids.

  3. Its precursor corticotropin-releasing hormone is released from the posterior pituitary gland.

  4. Human ACTH has a molecular weight of 540 atomic mass unit.

  5. Excessive secretion of ACTH causes Addison's disease.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

This option is correct because ACTH consists of 39 amino acids.

Multiple choice

Islets of Langerhans are important because they produce

  1. HCl

  2. Ptyalin

  3. Rennin

  4. Insulin

  5. Bile
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Islets of Langerhans are clusters of endocrine cells within the pancreas. Beta cells produce insulin (lowers blood glucose), alpha cells produce glucagon (raises blood glucose), and delta cells produce somatostatin. HCl is produced by stomach parietal cells, ptyalin (salivary amylase) by salivary glands, renin by stomach chief cells, and bile by liver hepatocytes.

Multiple choice

Adreno cortico trophic hormone (ACTH) is secreted by

  1. thyroid

  2. pituitary

  3. adrenal

  4. pancreas
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Adrenocorticotropic hormone (ACTH) is produced and secreted by the anterior pituitary gland (adenohypophysis). ACTH stimulates the adrenal cortex to produce cortisol, a stress hormone. The thyroid produces T3/T4 and calcitonin, adrenal medulla produces epinephrine/norepinephrine, and pancreas produces insulin/glucagon.

Multiple choice

ACTH is secreted by

  1. pineal body

  2. anterior lobe of the pituitary gland

  3. posterior lobe of the pituitary gland

  4. thymus

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Adrenocorticotropic hormone (ACTH) is specifically produced by corticotrophs in the anterior lobe of the pituitary gland (adenohypophysis). The posterior lobe (neurohypophysis) stores and releases oxytocin and ADH produced by the hypothalamus. The pineal body produces melatonin, and the thymus produces thymosin involved in immune development.

Multiple choice

Which one of the following does not secrete any hormone?

  1. Thyroid

  2. Ovary

  3. Testes

  4. Spleen
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The spleen is a lymphatic organ involved in filtering blood, recycling old red blood cells, and supporting immune function - it does NOT produce hormones. The thyroid gland secretes thyroxine (T4) and triiodothyronine (T3), the ovaries produce estrogen and progesterone, and the testes produce testosterone. All options except the spleen are endocrine glands with well-defined hormonal secretions.