Endocrine System Function

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The Endocrine System

The endocrine system is made up of glands that secrete hormones, or chemical messengers that create long lasting effects all around the body.

The endocrine system is made up of a series of glands that produce chemical substances known as hormones.
Like neurotransmitters, hormones are chemical messengers that must bind to a receptor in order to send their signal.
But unlike neurotransmitters, hormones are secreted into the bloodstream and travel around the body, affecting any cells that have receptors for them. The effects of hormones are widespread.
Also, hormones are slower to take effect and tend to be longer lasting.

Hormones are involved in regulating all sorts of bodily functions.
They are ultimately controlled through interactions between the hypothalamus (in the central nervous system) and the pituitary gland (in the endocrine system).
Imbalances in hormones are related to a number of disorders.

The pituitary gland descends from the hypothalamus at the base of the brain, and acts in close association with it.
The pituitary is often referred to as the “master gland” because its messenger hormones control all the other glands in the endocrine system (although it mostly carries out instructions from the hypothalamus).
In addition to messenger hormones, the pituitary also secretes growth hormone, endorphins for pain relief, and a number of important hormones that regulate fluid levels in the body.

The thyroid gland is located in the neck. It releases hormones that regulate growth, metabolism, and appetite.
Thyroid disorders such as hyperthyroidism or Grave's disease, where the thyroid secretes too much of the hormone thyroxine, can cause symptoms such as weight loss and agitation.
Fortunately, it's easy to treat the disorders with medication that reestablishes a healthy balance of thyroid hormones.

The adrenal glands are located on top of the kidneys and secrete hormones involved in the stress response, such as epinephrine (adrenaline) and norepinephrine (noradrenaline).
The pancreas is an organ that secretes hormones that regulate blood sugar levels: insulin, which lowers levels, and glucagon, which raises them.
People who suffer from diabetes do not produce enough insulin. This means they have to take medications that stimulate or replace insulin production. They must also closely control the amount of sugars and carbohydrates they eat.

The gonads secrete sexual hormones, which are important in reproduction. They also mediate both sexual motivation and behaviour.
The female gonads are the ovaries; the male gonads are the testes.
Ovaries secrete oestrogens and progesterone, and the testes secrete androgens, such as testosterone.

The pineal gland is a small pea shaped gland in the brain. Its main function is the production and regulation of melatonin, which is important for regulating sleep.
Parathyroid glands lie behind the thyroid glands and produce and regulate the parathyroid hormone, which regulates the body's levels of the minerals calcium and phosphorus.
Thymus glands are in the centre of the chest. They produce progenitor cells, which mature into T-cells, and are important for the immune system.