can you tell me more about the hormone you just mentioned?
The thyroid gland secretes three hormones: the two thyroid hormones – triiodothyronine (T) and thyroxine (T) – and a peptide hormone, calcitonin. The thyroid hormones influence the metabolic rate and protein synthesis, and in children, growth and development.
Thyroid
The thyroid gland secretes three hormones: the two thyroid hormones – triiodothyronine (T) and thyroxine (T) – and a peptide hormone, calcitonin. The thyroid hormones influence the metabolic rate and protein synthesis, and in children, growth and development. 
where is iodine found on the periodic table In the Halogen group what are some of its uses? Elemental iodine is used as a disinfectant; iodine compounds are used as catalysts, animal feed supplements, stabilisers, dyes, colourants etc. can it be poisonous? Yes - Elemental iodine is toxic if taken orally undiluted. The lethal dose for an adult human is 30 mg/kg, which is about 2.1–2.4 grams for a human weighing 70 to 80 kg is it an important component for a humans healthy life? Yes -  It is required for the synthesis of the growth-regulating thyroid hormones thyroxine and triiodothyronine
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Thyroid [SEP] Introduction
During migration, the thyroid remains connected to the tongue by a narrow canal, the thyroglossal duct. At the end of the fifth week the thyroglossal duct degenerates, and over the following two weeks the detached thyroid migrates to its final position. Thyroid disorders include hyperthyroidism, hypothyroidism, thyroid inflammation (thyroiditis), thyroid enlargement (goitre), thyroid nodules, and thyroid cancer. Hyperthyroidism is characterized by excessive secretion of thyroid hormones: the most common cause is the autoimmune disorder Graves' disease. Hypothyroidism is characterized by a deficient secretion of thyroid hormones: the most common cause is iodine deficiency. In iodine-deficient regions, hypothyroidism secondary to iodine deficiency is the leading cause of preventable intellectual disability in children.