The thyroid, rather than being a separate "part" of the endocrine system is a major player of the whole endocrine system which regulates metabolism, growth, development and puberty, tissue function and moods. It does this by secreting thyroid hormones that regulate the speed in which body's chemical functions proceed (metabolic rate).
Technically speaking, the thyroid gland regulates or in some way participates in the process of the following 14 body functions:
- regulates basal metabolic rate
- regulates body temperature
- regulates appetite
- promotes expulsion of glucose for energy
- stimulates protein synthesis
- increases lipolysis
- regulates cholesterol levels
- maintains standards for cardiac function
- promotes normal neuronal development in
the fetus and infants
- promotes normal neuronal function in
- enhances effects of sympathetic nervous
- promotes body and skeletal growth
- promotes development of muscles and
- regulates standards for female
reproduction and lactation
For as small as the thyroid is in physical size, it does quite a bit for our bodies. So just how does it do all this?
The thyroid gland is located in the front of your neck just below the Adams Apple. It is wrapped around the trachea (windpipe) and has a shape similar to that of a bow tie or butterfly. Its only purpose is to produce hormones which are introduced through the blood effecting metabolism throughout our entire body. The thyroid gland produces its two most important thyroid hormones, thyroxin (T4) and triiodothyronine (T3), from iodine which it gets from a diet of seafood and salt. Although the thyroid produces more T4 than T3 hormones (approximately 10:1 ratio) the T3 hormone is the more biologically potent of the two. Once introduced into the blood from the thyroid gland, a large portion of the T4 hormone is then converted into T3 hormone. The T3 hormone is the actual hormone affecting the body's metabolism.
The thyroid gland works in conjunction with two other glands, the hypothalamus gland (the area of the brain that controls body temperature, hunger and thirst) and the pituitary gland, located at the base of the brain, which acts as a regulator to the output of the thyroid glad. Hormones produced from each gland signals the next gland to produce its hormone. So the hypothalamus gland produces a hormone called TRH which sends a signal to the pituitary gland to produce a hormone called TSH which in turn signals the thyroid to produce T4 and T3 hormones. In addition to the signal from the TRH hormone from the hypothalamus gland, the pituitary gland senses the levels of T4 and T3 hormones in the blood and signals the thyroid gland by the amount of TSH hormone it releases to either increase or decrease the production of T4 and T3 hormones.
Because of the wide influence the thyroid has to the rest of the body, it is essential that the thyroid be kept in good health at all times. A dysfunctional thyroid can escalate, causing further dysfunction and damage to other organs of the body, and in some cases, if left unattended, a dysfunctional thyroid can become fatal with a heart attach
By Dennis Earle