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 animal behaviour ethology natural selection coordination in human beings- chemical control endocrine system in humans

The main function of prolactin hormone is to

  1. Influence the activity of thyroid gland

  2. Control development of Graffian follicles

  3. Initiate and maintain secretion of milk by mammary gland

  4. Cause ejection of milk
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Prolactin, also called as luteotropic hormone (LTH) or luteotropin, is a protein hormone produced by the pituitary gland of mammals, that acts with other hormones to initiate secretion of milk by the mammary glands. 

Multiple choice biology animal behaviour ethology natural selection coordination in human beings- chemical control endocrine system in humans

Which of the following hormones stimulates the production of milk?

  1. LH

  2. Prolactin

  3. Oxytocin

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

Prolactin is the hormone that stimulates milk production. During pregnancy, prolactin stimulates growth of the breast, but high estrogen and progesterone secretion prevent milk production. After delivery, estrogen and progesterone levels drop, and prolactin stimulates the secretion of milk by alveolar cells in the breast.

Multiple choice biology animal behaviour ethology natural selection coordination in human beings- chemical control endocrine system in humans

Some hormones check the milk from being secreted by the mammary glands till the birth of young ones even though the glands are all prepared to do so. They are

  1. Progesteron and prolactin

  2. Prolactin and FSH

  3. Oestrogen and prolactin

  4. Oestrogen and progesteron
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Progesterone and prolactin check the milk from being secreted by the mammary glands till the birth of young ones even though the glands are all prepared to do so. Progesterone is a hormone released by the corpus luteum in the ovary. Changing progesterone levels can contribute to abnormal menstrual periods and menopausal symptoms. Prolactin is a hormone named originally after its function to promote milk production (lactation) in mammals in response to the suckling of young after birth. It has since been shown to have more than 300 functions in the body. These can be divided into a number of areas: reproductive, metabolic, regulation of fluids (osmoregulation), regulation of the immune system (immunoregulation) and behavioural functions.
At birth, prolactin levels remain high, while the delivery of the placenta results in a sudden drop in progesterone, oestrogen, and HPL levels.
Multiple choice biology animal behaviour ethology natural selection coordination in human beings- chemical control endocrine system in humans

Continued secretion of milk is regulated by

  1. Prolactin

  2. Oestrogen

  3. Progesterone

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

Prolactin (PRL) is a hormone that stimulates milk production. Prolactin also plays an essential role in metabolism, regulation of the immune system, and pancreatic development.

Therefore, the correct answer is option A.

Multiple choice biology animal behaviour ethology natural selection coordination in human beings- chemical control endocrine system in humans

To yield more milk, cow is injected with

  1. Sorbitol

  2. Prolactin

  3. Gonadotrophs

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

Prolactin (also called as luteotrophic) hormone is associated with lactation (secretion of milk from the mammary gland). It is a hormone released by the pituitary gland that stimulates breast development and milk production in women. Therefore, to yield more milk cow is injected with prolactin hormone. 

Sorbitol is a sweetener found in some fruits (like apple, pear etc.). 
Gonadotroph is a type of basophil in the adenohypophysis (anterior pituitary gland) whose granules secrete FSH (follicle-stimulating hormone) and LH (luteinizing hormone). 
Stilbesterol is synthetic estrogen used in hormone therapy, as a post-coital contraceptive, and as a growth-promoting agent for livestock. 
Therefore, the correct answer is option B.

Multiple choice biology control and coordination in living organisms hormones coordination in human beings- chemical control endocrine system in humans

Which of the following hormones does not have a particular target organ in the body?

  1. Growth hormone

  2. TSH

  3. Oxytocin

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

Growth hormone secreted by the anterior pituitary has a widespread effect in the body. It stimulates growth of various body cells, promotes protein anabolism, absorption of calcium from bowel and conversion of glycogen to glucose.

Multiple choice biology control and coordination in living organisms hormones coordination in human beings- chemical control endocrine system in humans

____________ acts a transporter of hormones in animals.

  1. Spinal fluid

  2. Blood

  3. Cell

  4. All of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

  • Blood is the medium of transport of animal hormones. The tissues that produce the hormones are known as the effectors while those tissues that are influenced by the effectors are called targets. Hormones are of low molecular weight and they diffuse readily. 
  • The effects brought about by the hormones are not permanent as they get readily oxidized. 

Therefore, the correct answer is option B.

Multiple choice biology control and coordination in living organisms hormones coordination in human beings- chemical control endocrine system in humans

Chemically hormones are 

  1. Biogenic amines

  2. Proteins, steroids and biogenic amines

  3. Proteins only

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

Hormones are a diverse group of biochemicals, which perform a variety of roles in biological systems. Hormones are produced in endocrine glands. Hormones are responsible for maintenance of internal balance and developmental changes in the animal body. 

Chemically, hormones may be peptide (e.g., insulin), amines (e.g., catecholamines), proteins (e.g., growth hormone), steroid hormones (e.g., androgens). 

Multiple choice biology control and coordination in living organisms hormones coordination in human beings- chemical control endocrine system in humans

Hormones are

  1. Produced in low amount

  2. Sometimes diffusible

  3. Non-antigenic

  4. All of the above

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

Hormones are powerful. It takes only a tiny amount to cause big changes in cells or even whole body. Hormones are chemicals produced by special cells in glands and other organs of the body; most hormones are produced by cells in the endocrine glands. These hormones, which are produced in very small amounts, are released into the bloodstream and travel to the target organ or tissue where they exert their effect. That is why too much or too little of a certain hormone can be serious. Not all the hormones are easily diffusible. Among the diffusible lipid-soluble molecules are steroid hormones. Hormones are nonantigenic that is no antibody formation occurs against hormones.

Multiple choice biology control and coordination in living organisms hormones coordination in human beings- chemical control endocrine system in humans

Hormones are

  1. Internal secretion mostly discharged in the blood by endocrine glands

  2. Secretion of endocrine glands

  3. Chemical substances secreted into the gut

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

Hormones are special chemical messengers in the body that are created in the endocrine glands like Thyroid gland produces thyroxine and calcitonin. 

Hormones are secreted directly into the blood, which carries them to organs and tissues of the body to exert their functions. Thus, the correct answer is option A.

Multiple choice biology control and coordination in living organisms hormones coordination in human beings- chemical control endocrine system in humans

A hormone is

  1. An enzyme

  2. A chemical messenger

  3. Both A and B

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

Hormone is a chemical messenger produced in the body that controls and regulates the activity of certain cells or organs. Hormones are secreted from the endocrine glands in the body. The glands are ductless, so hormones are secreted directly into the bloodstream. 

Multiple choice biology control and coordination in living organisms hormones coordination in human beings- chemical control endocrine system in humans

Which of the following is a hormone?

  1. Vitamin D

  2. Thyroxine

  3. Adrenaline

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

Vitamin D is a hormone produced by the kidneys that help to control the concentration of calcium in the blood and is vital for the development of strong bones. Thyroxine, also called as 3,5,3,5-tetraiodothyronine, or $T _ 4$, is one of the two major hormones secreted by the thyroid gland. Epinephrine, more commonly known as adrenaline, is a hormone secreted by the medulla of the adrenal glands.

Multiple choice biology control and coordination in living organisms hormones coordination in human beings- chemical control endocrine system in humans

Which of the following is first aid hormone? 

  1. Vitamin D

  2. Catecholamines

  3. Kinins

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

The local hormones are known as kinins, which are released to overcome changes in body tissues. Kinins help in vasodilation and increase blood supply to the affected part, causing a mild local pain. Thus, they act as the first aid of the body. The sensation of pain at the time of stinging by a poisonous insect, burning or internal injury is due to kinins. So, they are called, first aid hormones.

Multiple choice biology control and coordination in living organisms hormones coordination in human beings- chemical control endocrine system in humans

Which one of the following does not match in biological category of chemical substance?

  1. Gastrin

  2. Thyroxine

  3. Oxytocin

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

The chemical substances that are secreted by cells/tissues or glands are categorised as biological substances. It includes digestive juices, hormones and other secretions. Gastrin, thyroxin and oxytocin are the hormones secreted by stomach, thyroid gland and posterior pituitary respectively. These are biochemical substances. Creatinine is a breakdown product of creatine phosphate and does not fall under the biological category of chemical substances. Thus, the correct answer is D.