THE PART OF HUMAN BODY - IMPORTANT
the thyroid is a small gland located below the skin and muscles at the front of the neck. It's brownish red, with left and right halves (called lobes) that look like a butterfly's wings. It's light like a butterfly, too, and usually weighs less than an ounce.
As small as it is, though, the thyroid has an enormously important job to do, especially for teens. It manufactures the hormones that help control metabolism and growth. To do its job, the thyroid needs a chemical element called iodine that the body absorbs from the foods you eat and the water you drink. The entire body contains about 50 milligrams of iodine. About 1/5 to 1/3 of that supply (10 to 15 milligrams) is stored in your thyroid. The thyroid combines the iodine with tyrosine (an essential amino acid) to make important hormones. Thyroid hormones are released from the gland and travel through the bloodstream to your body's cells. They help control the growth and the structure of bones, and many other body functions. By helping your cells convert oxygen and calories into the energy they need to work properly, these hormones are important in determining if your body will mature as it should. What Is Thyroid Disease?
Thyroid disease occurs when the thyroid gland doesn't supply the proper amount of hormones needed by the body. If the thyroid is overactive, it releases too much thyroid hormone into the bloodstream, resulting in hyperthyroidism. ("Hyper" is from the Greek, meaning "over" or "above.") Hyperthyroidism causes the body to use up energy more quickly than it should, and chemical activity (like metabolism) in the cells speeds up. An underactive thyroid produces too little thyroid hormone, resulting in hypothyroidism. ("Hypo" means "under" or "below.") When the amount of hormone released into the bloodstream is below normal, the body uses up energy more slowly, and chemical activity (metabolism) in the cells slows down. Although they are two different...
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