Endocrine System – Concept, function and diseases


We explain what the endocrine system is and its main functions. In addition, the glands that compose it and possible diseases.

Endocrine system
The endocrine system generates and distributes hormones through the bloodstream.

What is the endocrine system?

It is known as endocrine system or system of internal secretion glands to the set of tissues and organs of the human body (and other higher animals) responsible for the generation and distribution through the bloodstream of substances destined to the regulation of certain functions of the organism, known as hormones.

Similar to the nervous system, the endocrine system operates on the basis of distant impulses, but instead of being nervous (electrical), they are chemical. These chemical signals are hormones, responsible for activating, regulating or inhibiting certain actions and processes of the body, such as growth, tissue production, metabolism or the development and functioning of the reproductive organs, among others.

This hormonal system is made up of internal organs known as endocrine glands or organs, which generate their hormones and substances and release them in the body, either locally (such as the glands of the skin) or internally (through the blood system). This includes organs such as the thymus or pancreas, or smaller structures such as the pituitary gland located in the brain.

What’s more, this system is related to the nervous and digestive system, among others, thus constituting a complex response network of the body, which, for example, in stressful, erotic or resting situations, generates various hormones to enhance the capabilities of the human body.

Endocrine system function

Endocrine system
The pituitary gland secretes hormones to regulate homeostasis.

As stated before, the primary function of this system is the regulation of complex biochemical processes in the body, either before a certain external stimulus, or simply as part of life. This affects, for example, growth, development and sexual behavior, digestion, sleep and other areas of vital importance.

In general, the hormones released by the endocrine system can have functions of the following type:

  • Stimulants They activate or initiate biochemical cycles, or stimulate certain behaviors in the body’s tissues. For example, the hormone prolactin induces the production of milk in the maternal breasts.
  • Inhibitory. They exercise the opposite role: they inhibit, stop, decrease the production of some substance or a certain behavior of the body tissue. For example: the hormone somatostatin it inhibits the production of more growth hormones in the body, thus stopping body growth.
  • Antagonists They regulate a body process based on stimulating or inhibiting it, or producing opposite but simultaneous effects. For example, hormones insulin and glucagon regulate the metabolism of sugar, acting at the same time to increase or decrease its levels.
  • Synergistic. Sometimes the joint presence of two hormones increases the effect of the first, that is, they enhance each other to achieve more intense effects. For example: hormones hGH and T3 / T4 produced by the thyroid gland.
  • Tropics They allow the alteration or control of other endocrine tissues, serving as a chemical messenger in the body. For example: the hormone gonadotropin it triggers ovulation in women and spermatogenesis in men, when they are ready to start reproducing.

Glands of the endocrine system

Endocrine system
The adrenal glands regulate responses to stress.

The endocrine system is made up of many endocrine glands and organs. The main ones are the following:

  • Pineal gland. Also called the epiphysis or conarium, it is at the base of the brain next to the insertion of the spinal cord, and is common to all vertebrates. It produces hormones responsible for sleep and circadian rhythms.
  • Pituitary gland. Also known as the pituitary, it is responsible for secreting hormones necessary to regulate homeostasis, including tropic hormones that regulate other endocrine tissues. It is located at the base of the skull, in a bony chair of the sphenoid bone.
  • Thyroid gland. Located just below the Adam’s apple, in the throat and above the windpipe, it is responsible for regulating metabolism and nuancing the body’s sensitivity to other hormones.
  • Kidney glands. Pyramidal in shape, it is found in par on the kidneys, and is responsible for regulating responses to stress, secreting hormones such as cortisol and adrenaline, which physically prepare the body for a dangerous situation.
  • Scam This is a lymphoid (immune system) organ located in the torso, in front of the heart, and behind the breastbone.
  • Pancreas. A larger organ, located in the abdomen, secretes digestive enzymes to contribute to the absorption of nutrients, as well as hormones that regulate the metabolism of sugars (insulin and glucagon).
  • Sex glands. Ovaries and testes, for women and men respectively, are the organs where reproductive cells and hormones that prepare sexual maturation during puberty are generated.
  • External glands. Those located on the skin, are responsible for lubricating it and keeping it fresh, also spilling hormones that fulfill social roles and protection of the epidermis.

Endocrine system diseases

Endocrine system
Hyperthyroidism occurs when the thyroids speed up the metabolism too much.

The endocrine system can suffer from different disorders, which cause it to malfunction. They usually consist of overproduction or underproduction of hormones. Some examples are:

  • Mellitus diabetes. Disease that consists of the underproduction of insulin (or production of poor quality hormone) that is unable to regulate the level of sugar in the blood.
  • Hyperthyroidism The thyroid produces too many hormones and speeds up metabolism too much.
  • Hypothyroidism The thyroid secretes very little hormones and slows down metabolism too much.
  • Crushing’s disease. The adrenal glands secrete dangerous excess hormones.