The endocrine system is made up of endocrine glands that produce hormones that transmit information between the organs. It is the hormones of the thyroid gland, pituitary gland, adrenal glands, ovaries, pancreas, and pineal glands that determine your he alth, mood and appearance. If your hormonal balance is disturbed, you start to feel worse and get sick.

Contents:

  1. Endocrine system: structure and operation
  2. Endocrine system: hormone production
  3. Endocrine system: hormones secreted by the hypothalamus
  4. Endocrine system: hormones secreted by the pineal gland
  5. Endocrine system: hormones secreted by the pituitary gland
  6. Endocrine system: thyroid hormones
  7. Endocrine system: hormones secreted by the parathyroid glands
  8. Endocrine system: hormones secreted by the thymus
  9. Endocrine system: hormones secreted by the pancreas
  10. Endocrine system: hormones secreted by the adrenal glands
  11. Endocrine system: hormones produced by the ovaries
  12. Endocrine system: hormones secreted by the testicles

The endocrine system consists of endocrine glands (endocrine glands), which are responsible for secreting hormones. It is a control system consisting of: the pituitary gland, thyroid gland, parathyroid glands, pancreas, adrenal glands and ovaries in women and testes in men.

Both excess and deficiency of hormones disturb homeostasis - the body's internal balance.

The command center, the pituitary gland, controlled by the hypothalamus, determines how much and what hormone our body needs. The pituitary gland receives information about hormone reserves and their deficiency. The hypothalamus decides whether the amount of hormones is sufficient. If one is missing, it orders the pituitary gland to start releasing a stimulating hormone that will stimulate a specific gland to work harder. If there is too much of something, the hypothalamus says "stop".

Endocrine system - structure and operation

The operation of the endocrine system (the endocrine system) is a remarkable system of secreting hormones that act as messengers - they enable communication between different organs. If this system is working fine, the whole body is functioning smoothly. When the balance of the system is disturbed, the mood lowers, we look worse, we start to get sick.

When the endocrine glands produce hormones, they donate them to the blood for a specific purpose: to deliver information and commands to specific cells, tissues, and organs.

Pituitary hormones tell the thyroid gland, pancreas, adrenal glands, and ovaries what to do. Then each of these organs starts producing its own hormones that go where they are needed. For example, in times of severe stress, the adrenal glands send adrenaline to the heart, which mobilizes us to exercise. When the transmission of information is delayed, the body cannot react to the changing situation.

Endocrine system: hormone production

Hormones are made in the endocrine glands and then released into the bloodstream. They affect cells equipped with a specific receptor. Some of these substances are also produced by cells of the immune system, nervous system and many other organs. The endocrine glands, or endocrine glands, are:

  • pituitary gland
  • pineal gland
  • thyroid
  • parathyroid
  • thymus
  • adrenal glands
  • pancreas
  • ovaries and testicles
Worth knowing

Role of the hypothalamus in hormonal regulation

The hypothalamus - the lower part of the diencephalon, where liberins and statins, hormones influencing the pituitary gland, are synthesized, plays a major role in hormonal regulation. The pituitary gland is a tiny gland in the center of the skull that connects to the hypothalamus. The nerve part of the pituitary gland is considered part of the hypothalamus because it stores two of the hormones produced in the nucleus of the hypothalamus, vasopressin and oxytocin. Vasopressin controls the body's water supply and prevents its excessive excretion in the urine. Oxytocin, on the other hand, causes uterine contractions during childbirth and orgasm, supports the outflow of milk in lactating women, and awakens the caring instinct.

Endocrine system: hormones secreted by the hypothalamus

  • Liberins - releasing hormones, stimulate the pituitary gland to secrete hormones:

- somatoliberin - releases growth hormone
- corticoliberin - releases corticotropin
- gonadoliberin - influences the secretion of gonadotrophins (FSH and LH)
- thyreoliberin - influences the secretion thyrotropin

  • Statins - hormones that inhibit the secretion of hormones by the pituitary gland

- somatostatin inhibits the release of growth hormone and thyrotropin
- dopamine - prolactin, as well as thyrotropin.

  • Kisspeptin - known to affect puberty, menstrual disorders, fertility, plays a role in inhibiting cancer development, but still remainsa rather mysterious substance - there is a very high probability that the next few years will bring more reports about the impact of kisspeptin on the human body.

Endocrine system: hormones secreted by the pineal gland

  • melatonin (sleep hormone) - is involved in regulating the circadian rhythm of sleep and wakefulness, prepares the body for sleep after dark

Endocrine system: hormones secreted by the pituitary gland

  • somatotropin (growth hormone) - in a developing organism it is responsible for the growth of tissues, and in a mature organism - for their regeneration
  • prolactin - regulates the sexual cycle, supports pregnancy and stimulates the mammary glands to produce milk
  • thyrotropin (TSH) - stimulates the thyroid to secrete its own hormones called thyroid hormones
  • corticotropin (ACTH) - stimulates the adrenal glands to produce hormones
  • folliculostimulin (FSH) - controls the maturation of eggs in women, and the production of sperm in men
  • luteinizing hormone (LH) - it causes ovulation in women, and in men, the secretion of testosterone in the testes
  • melanotropin - stimulates pigment cells to synthesize melanin, the skin pigment
Important

The term "hormone" comes from the ancient Greek wordhormeo- to move, stimulate. In 1905, the English physiologist Ernest Starling used this name for the first time for endocrine gland products. He conducted research aimed at proving the existence of substances controlling many life processes in the body. The first hormone was isolated in 1895 by a Krakow physiologist, prof. Napoleon Cybulski (together with Szymonowicz). He discovered a substance secreted by the adrenal glands, now called adrenaline.

Endocrine system: thyroid hormones

  • triiodothyronine (T3) and thyroxine (T4) - determine the proper course of many processes in the body, regulate body temperature and metabolism, take part in the synthesis of vitamins, stimulate the development of the skeleton and nervous system in fetal life and early childhood; thanks to them we digest better, we have a good mood, we are interested in sex; determine the appearance of skin and hair; thyroxine affects the formation of subcutaneous fat; if the thyroid is working poorly, you may suffer from insomnia, excessive sweating or palpitations, with hypothyroidism you will develop fatigue, hypersensitivity to cold, brittle hair
  • calcitonin - reduces the concentration of calcium in the blood, binding its excess in the bones and limiting its absorption in the small intestine

Endocrine system: hormones secreted byparathyroid glands

  • parathyroid hormone - takes part in the calcium metabolism: increases the concentration of calcium in the blood, if it is too low, releasing it from bones and teeth

Endocrine system: hormones secreted by the thymus

  • thymosin - affects the body's immunity; its secretion is stimulated by thyroid hormones; the thymus gradually disappears after puberty

Endocrine system: hormones secreted by the pancreas

  • insulin - lowers the concentration of glucose in the blood, allowing it to penetrate inside the cells and store in the liver; insulin is also involved in the transformation of proteins and fats
  • glucagon - acts opposite to insulin, increasing blood glucose levels, which prevents hypoglycaemia (low sugar)

Endocrine system: hormones secreted by the adrenal glands

  • adrenaline and noradrenaline - prepare the body for increased physical and mental effort in situations requiring a quick reaction, e.g. they accelerate the heart rate, improve blood supply to muscles, raise blood glucose levels, dilate bronchi and pupils - their concentration increases during stress
  • cortisol - weakens the activity of the immune system, has anti-inflammatory properties, increases blood glucose levels; enhances the effects of adrenaline and noradrenaline during stress
  • dehydroepiandrosterone (DHEA) - "quenches" the body's reaction to stress, has an antidepressant effect, accelerates the metabolism of fats, suppresses appetite, has a positive effect on the mind and the appearance of the skin
  • aldosterone - regulates the water and electrolyte balance in the body. Takes care of maintaining the proper level of sodium and potassium

Endocrine system: hormones produced by the ovaries

  • progesterone - prepares the uterus to implant a fertilized egg in it, supports pregnancy (prevents premature uterine contractions), inhibits endometrial growth under the influence of estrogens
  • estrogens (estradiol, estriol, estrone) - are responsible, among others, for for developing a typically female body structure, regulating the menstrual cycle, enabling the development of egg cells, influencing the sex drive and the appearance of the skin

Endocrine system: hormones secreted by the testicles

  • androgens (mainly testosterone) - determine the development of typically male features (body shape, low voice, facial hair, chest), proper functioning of the male reproductive system and increase sex drive
Worth knowing

Sex hormonesdo not appear in the body until puberty. Newborns of both sexes in the first daysThey often have enlarged mammary glands in their lives, and sometimes you can even see milky secretion leaking out of them. This is the effect of maternal estrogens, which, by passing through the placenta during pregnancy, stimulate the development of breasts in the newborn. It passes after a few or a dozen days, when the child has released an excess of maternal hormones.

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