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 biology the age of adolescence changes in body during adolescence hormone during puberty role of hormones in reproduction
If both the ovaries are removed from rat, then which of the following hormone is decreased in the blood?

  1. Oxytocin

  2. Prolactin

  3. Estrogen

  4. Gonadotropin releasing factor
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
A. Oxytocin is secreted from the posterior pituitary and helps in the contraction of uterus during childbirth and also stimulates release of milk from mammary glands i.e. lactation.
B. Prolactin, also known as lactogenic hormone is produced by the pituitary gland. This hormones stimulates the production of milk in mammary glands during pregnancy.
C. Estrogen is the female sex hormone secreted from ovarian follicles and stimulate the development of female secondary sex organs.
D. Gonadotropin releasing factor or hormone (GnRH) is secreted from hypothalamus and stimulates the release of Luteinizing hormone and Follicle stimulating hormone from the anterior pituitary.
Hence, if both the ovaries are removed from rat, then estrogen is decreased in the blood.
So, the correct answer is 'Estrogen'.
Multiple choice biology the age of adolescence changes in body during adolescence hormone during puberty role of hormones in reproduction

Due to deficiency of which hormone, bones become weak in females?

  1. Progesterone

  2. TSH

  3. ACTH

  4. Oestrogen
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Oestrogen is a female sex hormone secreted from ovarian follicles. It stimulates development of secondary sex organs and sexual characters in females. After menopause, oestrogen secretion is decreased in females which leads to osteoporosis. It is a condition in which bones become weak and brittle due to dissolution of calcium. Due to oestrogen deficiency, osteoclasts i.e. cells that breakdown bones, stay for longer period of time in body and hence cause dissolution of calcium from the bones. Due to this, bones become weak and fragile.
So, the correct answer is 'Oestrogen'
Multiple choice biology the age of adolescence changes in body during adolescence hormone during puberty role of hormones in reproduction

Example of sex hormones secreted by ovary is

  1. FSH and LH

  2. FSH, LH and progesterone

  3. Progesterone and oestrogen

  4. FSH, LH, progesterone and oestrogen
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

At puberty, hypothalamus releases gonadotrohphin releasing hormone (GnRH) which stimulates the anterior pituitary gland. the latter secrete the FSH/LH from the anterior pituitary gland.

FSH- Stimulate the growth of graffian follicle, maturation of ovum, secretion of estrogen by follicle cells. Estrogen, or oestrogen, is the primary female sex hormone. It is responsible for the development and regulation of the female reproductive system and secondary sex characteristics.

LH- The luteinising hormone stimulates release of ovum( ovulation), formation of corpus luteum in the empty follicle and secretion of progesterone from the corpus luteum. Progesterone suspends ovulation during pregnancy, maintains foetal connection with the uterine wall and controls development of foetus in the uterus. If fertilization fails, means no pregnancy so progesterone level decreases to restart the process of ovulation.

So, the correct answer is 'Progesterone and estrogen'.

Multiple choice biology the age of adolescence changes in body during adolescence hormone during puberty role of hormones in reproduction

Which one controls the secretion of estrogen?

  1. hCG

  2. Progesterone

  3. LH

  4. FSH
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
A. hCG (Human Chorionic Gonadotropin) is secreted from placenta and maintains corpus luteum. 
B. Progesterone is a steroid female sex hormone which is also known as pregnancy hormone. It maintains the inner lining of uterus which aids in implantation of embryo in the uterus. 
C. Luteinizing hormone or LH stimulates growth of ovarian follicles in females. In males this hormone is called interstitial cell stimulating hormone or ICSH and affects the Leydig cells of testes.
D. Follicle stimulating hormone (FSH) is secreted from the anterior part of pituitary gland. It stimulates the growth of ovarian follicles in females.
Estrogen is a female sex hormone secreted from ovarian follicles which are influenced by FSH.
So, the correct answer is 'FSH'.

Multiple choice biology the age of adolescence changes in body during adolescence hormone during puberty role of hormones in reproduction

The female hormone that causes deposition of fat in the breast, and hips and the growth of pubic hairs during puberty is

  1. Estrogen

  2. Progesterone

  3. Luteinizing hormone

  4. Follicle-stimulating hormone
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Estrogen, or oestrogen, is the primary female sex hormone. It is responsible for the development and regulation of the female reproductive system and secondary sex characteristics. Estrogens are responsible for the development of female secondary sexual characteristics during puberty, including breast development, widening of the hips, and female fat distribution. Estrogen, in conjunction with growth hormone and its secretory product insulin-like growth factor 1  is critical in mediating breast development during puberty.

So the correct option is 'estrogen'.

Multiple choice zoology control and coordination in living organisms adrenal gland thymus and adrenal gland adrenal glands

The secretion of aldosterone by adrenal cortex is directly controlled by

  1. Plasma $K^{+}$ concentration

  2. Plasma Ca concentration

  3. Level of blood angiotensin

  4. Both A and C
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Aldosterone secretion is primarily regulated by the renin-angiotensin-aldosterone system (RAAS) and directly by plasma potassium (K+) concentration. An increase in plasma K+ directly stimulates the adrenal cortex to release aldosterone.

Multiple choice zoology control and coordination in living organisms adrenal gland thymus and adrenal gland adrenal glands

Adrenal cortex also controls the carbohydrate metabolism through

  1. Adrenaline

  2. Noradrenaline

  3. Glucocorticoids

  4. Mineralocorticoids
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The adrenal cortex is located on the outer layer of the adrenal gland and makes different hormones, that help control the heart, kidneys, GI tract, bones, genitalia and immune system. 

These hormones control carbohydrate metabolism, muscular integrity, haemodynamic changes and sexual maturity. The cortex makes glucocorticoids, which are hormones, that control glucose production in the liver and protein breakdown in muscle. 

Multiple choice zoology control and coordination in living organisms adrenal gland thymus and adrenal gland adrenal glands

A steroid hormone which regulates glucose metabolism is 

  1. 11-deoxycorticosterone

  2. Cortisone

  3. Cortisol

  4. Corticosterone
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Cortisol or glucocorticoid hormone is a steroid hormone produced by the adrenal cortex. It is released in response to stress and a low level of blood glucose. Its functions are to increase blood sugar through gluconeogenesis and to aid the metabolism of fat, protein, and carbohydrate. 

Multiple choice zoology control and coordination in living organisms adrenal gland thymus and adrenal gland adrenal glands

Reabsorption of Na$^+$ is controlled by which one of the following hormones ?

  1. Aldosterone

  2. Oestrogen

  3. Glucocorticoids

  4. Testosterone
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Renal reabsorption of sodium ($Na^+$) uses Na-H antiport, sodium-glucose symport, sodium ion channels (minor). It is stimulated by angiotensin II and aldosterone, and inhibited by atrial natriuretic peptide.

Multiple choice zoology the endocrine system adrenal gland thymus and adrenal gland adrenal glands

Name the hormone released during the following events$:$
A frightened person

  1. Testosterone

  2. Thyroxine

  3. Adrenaline

  4. Growth hormone
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Adrenaline, also known as epinephrine, is a hormone, neurotransmitter, and medication. Adrenaline is normally produced by both the adrenal glands and certain neurons. It plays an important role in the fight-or-flight response by increasing blood flow to muscles, the output of the heart, pupil dilation response, and blood sugar level. It does this by binding to alpha and beta receptors. It is found in many animals and some single cell organisms. Hence, the hormone released by a frightened person is Adrenaline.
So, the correct answer is 'Adrenaline'.
Multiple choice zoology the endocrine system adrenal gland thymus and adrenal gland adrenal glands

Our body retains NaCl, during the periods of excessive heat. Which of the following triggers this action?

  1. Aldosterone

  2. Progesterone

  3. ACTH

  4. Epinephrine
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

  • Body fluid volume disturbances involve an imbalance of intake and loss.
  • Aldosterone plays a central role in the homeostatic regulation of blood pressure, plasma sodium (Na+), and potassium (K+) levels.
  •  It does so primarily by acting on the mineralocorticoid receptors in the distal tubules and collecting ducts of the nephron.
  •  It influences the reabsorption of sodium and excretion of potassium of the kidney, thereby indirectly influencing water retention or loss, blood pressure and blood volume.
  •  When dysregulated, aldosterone is pathogenic and contributes to the development and progression of cardiovascular and renal disease. Aldosterone has exactly the opposite function of the atrial natriuretic hormone secreted by the heart. Hence, Our body retains NaCl, during the periods of excessive heat and aldosterone triggers this action.
So, the correct answer is 'Aldosterone'.

Multiple choice zoology the endocrine system adrenal gland thymus and adrenal gland adrenal glands

Injury to adrenal cortex is not likely to affect secretion of

  1. Andlostenedione and dehydroepian-drosterone

  2. Adrenaline

  3. Cortisol

  4. Aldosterone
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Adrenaline is secreted from adrenal medulla in response to stress conditions in the body. Androstenedione and dehydroepiandrosterone (form of androgens), cortisol and aldosterone are corticoid hormones secreted by adrenal cortex. They are steroid hormones that regulate water balance and electrolyte balance in the body. Adrenal cortex secretes glucocorticoids (cortisol), mineralocorticoids (aldosterone) and sexocorticoids (androgens).   
So, the correct answer is 'Adrenaline'.
Multiple choice zoology the endocrine system adrenal gland thymus and adrenal gland adrenal glands

Hormone controlling Na$^+$ - K$^+$ ion concentration is 

  1. Aldosterone

  2. Antidiuretic hormone

  3. Progesterone

  4. Pitocin
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
A. Aldosterone is a mineralocorticoid hormone secreted from the adrenal cortex. It maintains the electrolyte balance in the body by reducing the loss of sodium through urine and sweat. Hence, it controls Na⁺ - K⁺ ion concentration.
B. Anti diuretic hormone (ADH), is secreted from the posterior part of pituitary gland. This hormone increases reabsorption of water in kidneys and this results in decreased rate of urine production.
C. Progesterone is a steroid female sex hormone which is also known as pregnancy hormone. It maintains the inner lining of uterus which aids in implantation of embryo in the uterus. 
D. Pitocin is synthetic form of oxytocin. Oxytocin is secreted from the posterior pituitary and helps in the contraction of uterus during childbirth and also stimulates release of milk from mammary glands i.e. lactation.
So, the correct answer is 'Aldosterone'.