Well, I thought it might be best to start with a brief overview of what the endocrine system is.
Overview
The endocrine system consists of several glands that secrete hormones into the bloodstream. The Pituitary gland is considered the 'master gland' of this system, mainly because some of the hormones it produces directly cause other glands to secrete their hormones.
The hormones produced by this system of glands help to control growth, development, mood and wellbeing, metabolism and reproductive functions of the body. They can also affect skin color, and the sense of smell and taste. So when a disorder occurs, there are wide variety of possible side effects that might occur.
Hormones Secreted By the Endocrine System
There's quite a few - here's the important ones...
| Gland Name | Location | Hormones produced / Function |
| Pituitary * | Base of the brain | GH, ACTH, TSH, LH, FSJ, Prolactin, ADH, Oxytocin |
| Thyroid | Neck | Thyroxine, Calcitonin, Tri-iodothyronine |
| Parathyroid (4 glands) | Neck | Regulates calcium |
| Adrenal | Kidneys | Cortisone, Adrenaline, Aldosterone |
| Pancreas | Mid Abdomen | Insulin, Glucagon |
| Ovaries | Lower abdomen | Oestrogen, progesterone / Produce eggs |
| Testes | Scrotum | Testesterone / sperm production |
* The hormones secreted by the pituitary gland are covered in more detail - click here for more information.
Hypothalamus
The hypothalamus, a part of the brain, controls the pituitary gland, which in turn controls many of the glands in the endocrine system. It releases hormones which are received by the pituitary gland (which in itself is attached to the hypothalamus by a thin stalk). These hormones are either stored in the pituitary gland for later use, or cause the gland to produce a particular hormone.
Generally speaking, hormones are produced by the hypothalamus by a process known as 'negative feedback'. For example, if the body temperature is low, the hypothalamus will secrete a hormone which in turn stimulates the pituitary gland to secrete Thyrotropin, which in turn stimulates the Thyroid gland to secrete Thyroxine. Thyroxine increases body metabolism, and thus body temperature. If body temperature is too high, the process will reverse, less Thyrotropin will be secreted, causing the Thyroid gland to secrete less Thyroxine, thus lowering body temperature.
Normally (and assuming everything is working well!), this process of negative feedback will maintain hormones at a constant level.