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 zoology endocrine system and chemical co-ordination parathyroid gland thyroid and parathyroid gland thyroid, parathyroid and thymus gland

Which of the following is the target of parathyroid hormone?

  1. Kidneys

  2. Bones

  3. Small intestine

  4. Pancreas

  5. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Parathyroid hormone regulates the level of calcium in the blood. It does this through its actions on the kidneys, bones and intestine. When  the blood calcium level is too low, the parathyroid glands release more parathyroid hormone (PTH). This causes the bones to release more calcium into the blood, increase the absorption of more calcium through food and reduces the amount of calcium released by the kidneys into the urine. 

Multiple choice biology control and coordination in living organisms different type of gland glands in humans coordination in human beings- chemical control

Given below is an incomplete table about certain hormones, their source glands and one major effect of each on the body in humans. Identify the correct option for the three blanks A, B and C.

Glands Secretion Effect on body
A Oestrogen Maintenance of secondarysexual character
Alpha cellsof Islets ofLangerhans B Raises blood sugar level
Anteriorpituitary C Over secretion leads togigantism

  1. A - Placenta, B - Glucagon, C - Calcitonin

  2. A - Ovary, B - Glucagon, C - Growth hormone

  3. A - Placenta, B - Insulin, C - Vasopressin

  4. A - Ovary, B -Insulin, C - Calcitonin
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The primary function of the ovary is the production of ova. In addition to it, ovary acts like an endocrine organ where it secretes oestrogen, progesterone under the influence of FSH. Oestrogen helps to develop and maintain the secondary sexual characters. Glucagon is secreted by alpha cells of islets of Langerhans which helps to maintain the glucose level by preventing glucose level from falling too low. The pituitary is the master gland of the body which controls the function of various other glands. It is divided into two lobes anterior and posterior. The posterior lobe secretes growth hormone, oversecretion of this hormone leads to gigantism and is mostly caused by a tumor in the gland. It results in the oversecretion of growth hormone. Thus the correct answer is option B.  


Multiple choice biology control and coordination in living organisms different type of gland glands in humans coordination in human beings- chemical control

Match the source gland with its respective hormone as well as the function and choose the correct option.

Sourcegland Hormone Function
(a) Thyroid Thyroxine Regulates blood calciumlevel
(b) Anteriorpituitary Oxytocin Contraction of uterusmuscles during child birth
(c) Posteriorpituitary Vasopressin Stimulates reabsorptionof water in the distaltubules in the nephron
(d) Corpusluteum Estrogen Supports pregnancy

  1. a

  2. b

  3. c

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

Vasopressin is secreted from the posterior pituitary gland in response to reductions in plasma volume, in response to increases in the plasma osmolality, and in response to cholecystokinin (CCK) secreted by the small intestine. Its two primary functions are to retain water in the body and to constrict blood vessels. Vasopressin regulates the body's retention of water by acting to increase water reabsorption in the collecting ducts of the kidney nephron

Multiple choice biology control and coordination in living organisms different type of gland glands in humans coordination in human beings- chemical control

Select the correct matched pair.

(a) Pineal gland -   TSH
(b) Corpus luteum - Secretes oxytocin
(c) Interstitial cells - Erythropoietin
(d) Cholecystokinin - Stimulates pancreatic enzymesecretions
(e) Thyroxine - Adrenaline

  1. a

  2. b

  3. c

  4. d

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

Cholecystokinin (CCK), formerly called as pancreozymin, is a digestive hormone released with secretin when food from the stomach reaches the duodenum. Cholecystokinin is secreted by cells of the upper small intestine. Its secretion is stimulated by the introduction of hydrochloric acid or fatty acids into the stomach or the duodenum. Cholecystokinin stimulates the gallbladder to contract and release stored bile into the intestine. It also stimulates the secretion of pancreatic juice.

Multiple choice biology control and coordination in living organisms different type of gland glands in humans coordination in human beings- chemical control

Match the list I with list II and choose the correct answer.
List I                                                   List II
A. Adenohypophysis                 (1) Epinephrine 
B. Adrenal medulla                    (2) Somatotropin 
C Parathyroid gland                   (3) Thymosin 
D Thymus gland                         (4) Parathormone

  1. A- 3, B- 1, C- 4, D- 2

  2. A- 1, B- 2, C- 3, D- 4

  3. A- 2, B- 1, C- 4, D- 3

  4. A- 4, B- 3, C- 2, D- 1
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The anterior lobe of the hypophysis (pituitary gland) is called as the adenohypophysis. This lobe contains cells, that produce prolactin, growth hormone (somatotropin), thyroid-stimulating hormone, follicle-stimulating hormone. 

Cells in the adrenal medulla synthesize and secrete epinephrine (also called adrenaline). 
Parathormone is a hormone that is made by the parathyroid glands and is critical to maintaining calcium and phosphorus balance. 
Thymosin is the hormone of the thymus, and it stimulates the development of disease-fighting T cells.

Multiple choice biology endocrine system and adolescence different type of gland glands in humans coordination in human beings- chemical control

Hormones are produced by

  1. Exocrine glands

  2. Endocrine glands

  3. Holocrine glands

  4. Apocrine glands
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
A. Exocrine glands are the glands that secrete their products through ducts.
B. Endocrine glands are the ductless glands which secrete their products directly into the blood.
C. Holocrine glands secrete their products in the cytoplasm which are released due to rupture of cell membrane.
D. Apocrine glands are generally present in the skin and secrete their products on the skin surface.
Hormones are produced by endocrine glands. They are secreted in the blood stream from which they are carried to their target organs.
So, the correct answer is 'Endocrine glands'.
Multiple choice biology endocrine glands different type of gland glands in humans coordination in human beings- chemical control

Hormones are ........... substances secreted in ........... quantities by .......... which acts on the effector organs.

  1. Electrical, large, endocrine gland

  2. Chemical, small, endocrine gland

  3. Electrical, large, exocrine gland

  4. Chemical, small , exocrine gland
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Hormones are organic chemical substances that are released or secreted by endocrine glands in one part of the body and sends out messages that affect cells in other parts of the body. They act as chemical messenger. The target organs or tissues are affected by and respond to only minute quantities of the hormones. Thus, only a small amount of hormone is required to alter cell metabolism. Major endocrine glands include pituitary, thyroid, parathyroids, pancreas, adrenals, testes or ovaries.

Thus, the correct answer is option B.

Multiple choice biology endocrine glands different type of gland glands in humans coordination in human beings- chemical control

Which type of signaling mechanism is most likely used for communication between two neighboring cells?

  1. Steroid hormones

  2. Molecules released in the extracellular space

  3. Endocrine signaling

  4. Molecules released in the bloodstream
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

  •  The extracellular ("outside of cell") ligand-binding, a hydrophobic domain extending through the membrane.
  • This type  of signaling mechanism is most likely used for communication between two neighboring cells is by extracellular space,
Hence, the type of signaling mechanism is most likely used for communication between two neighboring cells is by Molecules released in the extracellular space.
So, the correct answer is 'Molecules released in the extracellular space'.

Multiple choice biology endocrine glands different type of gland glands in humans coordination in human beings- chemical control

Hormones are produced by 

  1. Apocrine glands

  2. Endocrine glands

  3. Heterocrine glands

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

  • Apocrine glands are generally present in the skin and secrete their products on the skin surface.
  • Endocrine glands are the ductless glands which secrete their products directly into the blood.
  • Heterocrine glands are the glands which act both as exocrine and endocrine glands.For example, in humans, Pancreas is a heterocrine gland. It secretes insulin hormone into blood and act as endocrine gland and when it secretes digestive enzymes and juice through pancreatic duct, it acts as exocrine gland.
Hormones are the chemicals or signalling molecules that are produced by endocrine glands and secreted into blood stream from where they reach their target organs and cause a change in their function and regulation.
Hence, both options B and C are correct.
So, the correct answer is 'Both B and C'.

Multiple choice biology endocrine glands different type of gland glands in humans coordination in human beings- chemical control

Find out the correct statement. 

  1. Endocrine glands regulate neural activity but not vice versa.

  2. Neurons regulate endocrine activity but not vice versa.

  3. Endocrine glands regulate neural activity and nervous system regulates endocrine glands.

  4. Neither hormones control neural activity nor the neurons control endocrine activity.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

  • Nervous system is a coordinated network of nerve cells and fibres by which nerve impulses are transmitted throughout the body.
  • Endocrine system consists of glands that produce hormones. Hormones are secreted in the blood from where they reach the target organs and cause changes in their functioning and regulation.
In our body, nervous system and endocrine system jointly integrate all the activities as nervous system directs endocrine system to secrete hormones that act on the target organs.
So, the correct answer is 'Endocrine glands regulate neural activity and nervous system regulates endocrine glands.'.

Multiple choice biology endocrine glands different type of gland glands in humans coordination in human beings- chemical control

Which is not involved in endocrine secretion? 

  1. Leydig cell

  2. Lutein cell

  3. Parafollicular cells of thyroid

  4. Kupffer cells
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Endocrine secretion is the secretion of hormones from endocrine glands which are ductless glands and secrete hormones into blood stream. 
  • Leydig cells are present in testis and secrete testosterone hormone.
  • Lutein cells are present in corpus luteum in ovary and secrete progesterone hormone.
  • Parafollicular cells of thyroid gland secrete calcitonin hormone.
  • Kupffer cells are phagocytic cells in liver that destroy or breakdown red blood cells.
Hence, Kupffer cells are not involved in endocrine secretion.
So, the correct answer is 'Kupffer cells'.
Multiple choice biology endocrine glands different type of gland glands in humans coordination in human beings- chemical control

Which of these hormones are not secreted by an endocrine gland?

  1. ADH

  2. PTH
  3. T$ _4$

  4. ANF
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
A. ADH (Antidiuretic hormone) is secreted from posterior lobe of pituitary gland.
B. PTH (Parathormone) is secreted from parathyroid gland.
C. T4 or tetraiodothyronine is thyroxine hormone which is secreted from thyroid gland.
D. ANF (Atrial natriuretic factor) is a peptide hormone secreted from heart.
Endocrine glands are ductless glands which secrete hormones into blood stream. Heart is not an endocrine gland.
So, the correct answer is 'ANF'.
Multiple choice biology endocrine glands different type of gland glands in humans coordination in human beings- chemical control

Which one of the following statements is correct ?

  1. Neurons regulate endocrine activity, but not vice verse

  2. Endocrine glands regulate neural activity, and nervous system regulates endocrine glands

  3. Neither hormones control neural activity nor the neurons control endocrine activity

  4. Endocrine glands regulate neural activity, but not vice versa
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
The autonomous nervous system regulates the secretion of glands whereas the glands do not regulate the nervous system.

So, the correct answer is 'Neurons regulate endocrine activity, but not vice verse'.
Multiple choice biology endocrine glands different type of gland glands in humans coordination in human beings- chemical control

Which among the following is incorrect about the endocrine system?

  1. It relies on chemical messengers that travel through the bloodstream.

  2. It is a control system that has extremely rapid effects on the body.

  3. The hormones affect only certain "target" organs.

  4. It is involved in maintaining body homeostasis.

  5. Its organs secrete hormones directly into the bloodstream, rather than through ducts
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The endocrine system includes ductless glands that secrete hormones and release them directly into the blood. This makes option E correct about the system. Second messengers are the low molecular weight molecules that serve to transmit and amplify the signal of hormones, the first messenger, to initiate the downstream enzyme cascade inside the cell. Second messenger pathway is activated by binding of hormones to the receptor molecules present on the surface of target cells only. 

Hormones secreted by various endocrine glands maintain the normal functioning of target tissues/organs and thereby help to maintain homeostasis. 
Endocrine system effects are slow but long term. 
Therefore, the correct answer is option B.

Multiple choice biology for the continuity of generation fertilization in human being fertilization in humans human fertilization

The hormone responsible for inducing spermatogenesis and oogenesis is

  1. FSH

  2. Estrogen

  3. LH

  4. Androgen
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
  • Gonadotrophin regulating hormone (GnRH) secreted by the hypothalamus stimulates the release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) in male. 
  • FSH enters the testes stimulating the Sertoli cells which help to nourish the sperm cells that the testes produce to begin the process of spermatogenesis. Similarly in females, GnRH secreted by the hypothalamus stimulates the release of FSH, which stimulates the growth of egg cells, and LH, which signals for the ovulation of an egg from its follicle.