The Thyroid

The thyroid gland secretes thyroid hormones which control the speed at which the body's chemical functions proceed. Thyroid hormones control the metabolic rate by stimulating almost every tissue in the body to produce proteins, and by increasing the amount of oxygen that cells use. The thyroid gland needs iodine to function correctly, and this is obtained from the diet. Thyroid hormone production is controlled by a feedback mechanism via the pituitary gland (Berkow, Beers & Fletcher, 1997). First the hypothalamus, located in the brain just above the pituitary gland, secretes thyrotropin-releasing hormone; this causes the pituitary gland to produce thyroid-stimulating hormone; thyroid-stimulating hormone induces the thyroid gland to produce thyroid hormones. When the amount of circulating thyroid hormones reaches a certain level in the bloodstream, the pituitary gland produces less thyroid-stimulating hormone; when the blood level of thyroid hormones drops, the hypothalamus senses this and produces more thyrotropin-releasing hormone, which stimulates the pituitary to produce more thyroid-stimulating hormone. This is known as a negative feedback system.

. . .
d adjustments to the L-thyroxine dose. Overall IQ scores and behavioral assessments were average in these patients when compared to the normal population, but patients with significantly slower than normal bone development and lower blood thyroxine levels at birth tended to have lower IQ scores. Height, weight, and head size were normal for all patients. This suggests that lower doses of L-thyroxine nay be used successfully to treat congenital hypothyroidism. Treatment of hypothyroidism is with oral medications (Berkow, Beers & Fletcher, 1997). The preferred form of therapy is synthetic thyroid hormone, T4. Another form, desiccated thyroid (dried), is obtained from the thyroid glands of animals. Synthetic thyroid hormone is preferred because it is harder to control the dose of the animal extract because all pills do not contain the same amount. A study in Thailand looked at the underlying causes in 35 children with congenital hypothyroidism (Seeherunyong & Churesigaew, 1998). The study included 21 girls and 14 boys. Serum T4 and TSH levels, 24-hour 131I uptake, and technetium-99m thyroid scintigraphy were performed after discontinuation of synthetic thyroid hormone for four to six weeks. Athyrosis was found to be t
. . .

Some common words found in the essay are:
Choksi Colaco, Holub Jacob, IGF-I IGFBP-3, Beers Fletcher, Vogiatzi Kirkland, T4 TSH, , Voorhess MacGillivray, Overall IQ, congenital hypothyroidism, T4 T3, thyroid hormone, pituitary gland, thyroid gland, thyroid hormones, thyroxine levels, thyroid-stimulating hormone, magnetic resonance imaging, triiodothyronine thyroxine, thyroid function, resonance imaging, children congenital hypothyroidism, growth hormone-binding protein, berkow beers fletcher, beers fletcher 1997,
Approximate Word count = 2757
Approximate Pages = 11 (250 words per page)