Thyroid Disorders Essay Research Paper SummeryAccording to

Thyroid Disorders Essay, Research Paper

Summery

According to the American Thyroid Association, millions of Americans (especially women) suffer from a thyroid disorder, and many of them don.t even know it. In fact, thyroid disorders occur much more often than even many doctors realize. The butterfly-shaped thyroid is in the neck, its two .wings. wrapped around the windpipe just below the Adams. apple. This vitally important gland normally weighs less than an ounce, but it can have an enormous impact on your health. Think of it as your body.s metabolism regulator. It does the job by releasing two hormones, most of which is the iodine-containing hormone thyroxine. The hormones help regulate your heartbeat, body temperature, the smooth working of your muscles, how quickly you burn calories, how swiftly food moves through your digestive tract and more.

Normally, the thyroid doles out just the right amount of hormone to keep these processes humming smoothly. But in some cases it may become overactive and pump out too much hormone called hyperthyroidism. And on the other hand it may slow down and produce too little hormone called hypothyroidism.

Most thyroid problems-involving overactive or underactive glands-are caused by an autoimmune reaction. Normally the immune system functions to defend the body from invading microbes. In an autoimmune reaction, however, the immune system turns against the body itself and goes on the attack. In graves. disease the antibodies attach to the thyroid receptors and stimulate the thyroid to produce excessive amounts of thyroid hormones. In both cases serious imbalances in the body.s energy regulation system occur. The good news is that both kinds of thyroid problems respond well to treatment after they are diagnosed.

Introduction

Normally the thyroid gland is located in the front of the neck just below the Adam.s apple (Bayliss, 1982). This butterfly-shaped gland located at the base of your neck plays a role in your body.s metabolism. By releasing thyroid hormones, the thyroid actually regulates how your body uses fuel (Morgan 1996). The thyroid is an endocrine gland. Other endocrine glands include the pituitary gland, pancreas, ovaries in women and testes in men, the adrenal glands, and the parathyroid glands. The thyroid manufactures certain chemical substances (hormones) that are secreted into the bloodstream and induce an effect on cells and tissues elsewhere in the body (Bayliss 1982).

The thyroid makes two hormones- thyroxine, which because this chemical compound contains four iodine atoms is often called T4, and triiodothyronine which contains three iodine atoms thus calledT3 (Korte 1994). Both are secreted into the bloodstream and carried throughout the body. In many respects these thyroid hormones can be likened in their action to the speed control on a record player. They regulate the metabolic activity of all body cells and tissues. Too little thyroid hormone means that the body cells work at too slow a rate. The result is much the same as playing a 45r.p.m. record at 331/3 r.p.m.; it is slowed and sluggish. By contrast too much hormone induces the cells to work too fast, like playing a 45 r.p.m. record at 63 r.p.m. and the result is the .chipmunk. effect (Epps 1995). Although the two thyroid hormones influence the proper working of all body cells, their effect is particularly evident in certain functions (Foley 1993). For example growth and development, both physical and mental, depend upon the presence of an adequate amount of thyroxine. Without thyroxine a tadpole will not metamorphose into a frog, and without thyroxine a newborn baby will not grow properly nor will its brain develop properly. Thyroxine regulates the rate of oxygen consumption, which is another way of saying it controls the speed of activity of body cells(Morgan 1996).

The secretory activity of the thyroid gland is regulated by the pituitary gland.s secretion of thyroid-stimulating hormone (TSH or thyrotrophin). The pituitary gland is the size of a grape and lies at the base of the brain. It secretes many different hormones including the TSH. This hormone passes into the bloodstream and activates the thyroid gland to secrete more T4 and T3 (Thibodeau1992). As a result of this stimulation of the thyroid cells, the level of T4 and T3 in the bloodstream rises; the pituitary cells that secrete TSH sense this and the output of thyroid-stimulating hormone is reduced (Morgan 1996). This feedback control is similar to a thermostat that senses when the temperature in a house has risen to the required degree then turns off the furnace so the heat production is stopped or reduced. Vise versa, when the blood levels of T4 and T3 fall below a certain point, the TSH-secreting cells of the pituitary gland recognize this, and produce more TSH. This activates the thyroid cells to increase their output of T4 and T3 just as when rooms. temperature falls below a certain point the thermostat activates the furnace to produce more heat (Bayliss 1992).

Some diseases are specific or particular to the thyroid gland and do not, indeed cannot, occur elsewhere in the body. For example overactivity of the gland and underactivity are, in the symptoms produced, diseases only associated to the thyroid (Thibodeau 1992). Certain other disorders such as acute or subacute inflammation (thyroiditis) and cancers are not so specific to the