Biology · General Awareness

Human Endocrine System

1,530 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

Serotonin is released from

  1. enterochromaffin cells

  2. kupffer cells

  3. clara cells

  4. paneth cells

  5. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Enterochromaffin cells  release serotonin.

Multiple choice

Sometimes at the time of child birth relaxin hormone is given to facilitate the child birth. It helps in relaxing:

  1. tendons

  2. ligaments

  3. muscles

  4. all of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Relaxin is a hormone produced during pregnancy that specifically targets and relaxes the pelvic ligaments, particularly the pubic symphysis, to widen the birth canal. While it may have some effect on other tissues, its primary and most significant action is on ligament relaxation.

Multiple choice

Which of the following is the function of nor-epinephrine?

  1. To increase blood pressure

  2. Urine formation

  3. To increase secretion of adrenalin

  4. Both (1) and (2)

  5. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Norepinephrine is a neurotransmitter and hormone that acts as a vasoconstrictor, narrowing blood vessels and thereby increasing blood pressure. It is released by sympathetic nerve endings and the adrenal medulla as part of the fight-or-flight response. The other options are incorrect: urine formation occurs in kidneys, and norepinephrine does not directly stimulate adrenaline secretion.

Multiple choice

Which of the following is NOT a hormone?

  1. Calcitonin

  2. Melatonin

  3. Myosin

  4. Vasopressin

  5. Thyroxine
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Myosin is a principal contractile proteins found in muscle which forms thick filaments in myofibrils of muscle fibers.

Multiple choice

Which of the following hormone is secreted by adrenal cortex that regulates salt and water concentration in the kidney?

  1. Adrenalin

  2. Corticosterol

  3. Nor-epinephrine

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

Aldosterone is the mineralocorticoid hormone secreted by the adrenal cortex that specifically regulates sodium and water balance in the kidneys. Adrenalin (epinephrine) and nor-epinephrine are from the adrenal medulla and regulate stress responses, while Corticosterol is not a standard hormone name.

Multiple choice

The emergency hormone in humans is

  1. thyroxine

  2. adrenaline

  3. insulin

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

Adrenaline (epinephrine) is called the emergency hormone because it's rapidly released during stressful situations, triggering the fight-or-flight response. It increases heart rate, blood pressure, and energy availability while redirecting blood to essential organs.

Multiple choice

FSH and LH hormones together are called

  1. emergency hormones

  2. gonadotropic hormones

  3. neuro hormones

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

 Gonadotropins are glycoprotein polypeptide hormones secreted by gonadotrope cells of the anterior pituitary of vertebrates.This family includes the mammalian hormones follicle-stimulating hormone (FSH), luteinizing hormone (LH), and placental/chorionic gonadotropins human chorionic gonadotropin (hCG) and equine chorionic gonadotropin (eCG).

Multiple choice

Parathormone is secreted during :

  1. Increased blood calcium level

  2. Decreased blood calcium level

  3. Increased blood sugar level

  4. Decreased blood sugar level

  5. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Parathyroid hormone is secreted from the four parathyroid glands which are small glands in the neck, located behind the thyroid gland. Parathyroid hormone regulates calcium levels in the blood, largely by increasing the levels when they are too low. It does this through its actions on the kidneys, bones and intestine.

Multiple choice

Absorption of H2O in DCT is controlled by:

  1. ADH

  2. ACTH

  3. LH

  4. Oxytocin

  5. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

ADH is a hormone that is produced in a part of the brain called the hypothalamus. Absorption of H2O in DCT is controlled by ADH.

Multiple choice

Leydig cells of the testes are responsible for the production of:

  1. Primary Spermatocyte

  2. Testosterone hormone

  3. Leuteinizing Hormone

  4. Testosterone and Leuteinizing Hormone
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Leydig cells (also called interstitial cells) are specialized cells in the testes that synthesize and secrete testosterone in response to luteinizing hormone (LH) stimulation from the pituitary gland. LH itself is produced by the anterior pituitary gland, not by testicular cells. Primary spermatocytes are germ cells involved in sperm production, not hormone synthesis.

Multiple choice

For years, scientists have believed that a certain hormone produced by the human liver was triggered by Enzyme U, which is released in the pancreas. Recently, however, researchers in Belgium discovered that Enzyme U is always preceded by the release of Enzyme W in the brain, and hypothesized that Enzyme W, not Enzyme U, triggers the release of the liver hormone. If a second research project were set up to verify the findings of the Belgian researchers, which of the following test results would most seriously weaken their hypothesis?

  1. Enzyme W is released, but not followed by the release of Enzyme U, although the liver hormone is released.

  2. Enzyme U is released, but neither preceded by the release of Enzyme W, nor followed by the release of the liver hormone.

  3. Neither Enzyme W nor Enzyme U is released and the liver hormone is not released.

  4. Enzyme W is released, followed by the release of Enzyme U and the release of the liver hormone.

  5. Enzyme U is released and followed by the release of the liver hormone, although enzyme W is not released
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

(5) The Belgian Researchers' CONCLUSION: Enzyme W, rather than U, triggers the release of the liver hormone.THE EVIDENCE: Enzyme U is always preceded by the release of Enzyme W. It's a classic causality question. Remember the key issues. We want to weaken a causal claim - that Enzyme W releases the liver hormone - so we ask whether the cause always precedes the effect (it should) or whether another cause could be at work (it shouldn't). If we get test results that present the liver hormone and Enzyme U's release, but not the release of Enzyme W, we have the effect (the liver hormone) without the cause (Enzyme W). We also have a strong case for another cause (Enzyme U). These test results hammer the researchers' conclusion. An example of the effect without the cause destroys a causal claim-some other cause must account for the effect.