What are hormones?

Hormones are chemicals or biochemical messengers that are produced in small amounts in an organism and are secreted directly into the blood which carries them to the corresponding tissues and organs to exert their functions.


General Idea of ​​Hormones

  • The biochemical substances secreted in an organism that regulates metabolic functions and activities throughout the body are called hormones.
  • Hormones are usually secreted from certain types of cells, tissues and endocrine glands.
  • These biochemicals are usually transported, to sites in the body distant from their site of secretion, through blood and lymph.
  • Hormones are mainly composed of proteins, amino acids, steroids, etc. Hormones are not stored anywhere else in the body except at the source.
  • The word hormone is derived from the Greek word Hormacin or Hormas, which means to awaken or arouse.


  • A protein, amino acid or steroid-like biochemical substance that is secreted in small amounts from a particular cell group or endocrine gland.
  • They are usually transported through the blood, lymph, etc. to a specific part of the body away from the place of origin.
  • Hormones are chemicals that regulate metabolism and are destroyed once their activity is complete.

Characteristics of Hormones

[1] Nature: Hormones are a type of protein or steroid or amino acid biochemical substance, which acts far away from the secreted area (exception: local hormone).

[2] Consequences : The hormone acts like an organic catalyst, but after its activity, it is destroyed and quickly leaves the site.

[3] Storage: Hormones are not stored anywhere else in the body except in the excreted space.

[4] Amount: Hormones act in very small doses, but the duration of this action is long. Abnormalities are seen in the organism when hormones are secreted in amounts less than the required amount.

[5] Coordinators: Hormones act as chemical coordinators in the organism.

[6] Messengers: Hormones send chemical messages to cells; this is why hormones are called chemical messengers.

[7] Feedback: The secretion of one endocrine gland is indirectly regulated by another gland itself; this method called feedback.

[8] Dual controller: In some areas of the animal body, one of the hormones helps/stimulates a particular function while another one of the hormones inhibits the same function. Thus, the hormone acts as a dual-regulator in the animal body.

Fun Facts:

  1. Pituitary gland is known as the master of glands.
  2. There are two basic hormones known as estrogen and testosterone basically called men and women’s hormones respectively. Yet both the hormones are required by both genders.
  3. The system responsible for the hormones and its gland is known as the endocrine system.

Additional Questions:

  1. Why are hormones called ‘chemical adjusters’?
  2. Which hormone is secreted from the stomach?
  3. What is the function of the hormone called dopamine? Where is this hormone produced in the human body?

True or False:

  1. Hormones are produced in large amounts in human beings.
  2. Hormones do not increase the speed of reactions.
  3. Hormones are secreted through special types of cells and tissues.
  4. Hormones are transported to different places through water.
  5. The secretion of one gland is indirectly regulated by another gland.

Objective Quiz:

  1. Hormones are also called as ___________.
    1. Chemical messengers.
    2. Hormone regulators.
    3. Blood purifier.
    4. Hormone secretor.
  2. __________ acts as a coordinators in organism.
    1. Hormone.
    2. Water.
    3. Blood.
    4. Lymph.
  3. Hormones are transported to different places through __________.
    1. Blood and lymph.
    2. Water.
    3. Air.
    4. Oxygen.
  4. Hormones are produced in _________ in organism.
    1. Small amount.
    2. Large amount.
    3. Very large amount.
    4. None of the above.
  5. Hormones are the type of ___________.
    1. Steroid.
    2. Amino Acid.
    3. Protein.
    4. All off the above.

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