- BY Dr. Rajeev's Clinic
Our thyroid is a small butterfly - shaped gland situated at the base of the front of our neck . The lower two thirds of the lobes are connected by a thin band of tissue called the thyroid isthmus . The thyroid gland seretes three hormones ; the two thyroid hormones - Triodothyronine(T3) and Thyroxine(T4) and a peptide hormone calcitonin.
The thyroid hormoe influence the metabolic rate and protine synthesis and in children growth and development .
Secretion of the two thyroid hormones is regulated by thyroid - stimulating hormone (TSH) which is secreted from the anterior pituitary gland .
TSH is regulated by thyrotropin - releasing hormone (TRH) which is produced by the hypothalamus.
In the development of the embryo at 3-4 week gestational age the thyroid gland appears as an epithelial proliferation in the floor of the pharynx at the base of the tongue between the tuberculum impar and the copula linguae .
The primary function of the thyroid is the production of the iodine - containing thyroid hormones , triiodothyronine (T3) and thyroxine (T4). the thyroid hormons are created from iodine and tyrosine . The thyroid hormones have a wide range of effects on the human body . These include -
*METABOLIC - The thyroid hormones increse the basal metabolic rate and have effects on almost all body tissues . Appetite the absorption of substances and gut motility are all influenced by thyroid hormones . They increase the absorption in the gut generation uptake by cells and increse the number of free fatty acids .
*CARDIOVASCULAR - The hormones increase the rate and strength of the heartbeat . They increase the rate of breathing intake and consumption of oxygen and increse the activity of mitochondria .
*DEVELOPMENTAL - Thyroid hormones are important for normal development . They increase the growth rate of young people and cells of the developing brain are a major target for the thyroid hormones t3 and t4.
The thyroid hormones also play a role in maintaining normal sexual function ,sleep, and throught patterns. sexual function including libido and the maintenance of a normal menstrual cycle are influenced by thyroid hormones.