Thyroid hormone
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The thyroid gland secretes three main hormones: thyroxine, triiodothyronine and calcitonin.
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Thyroxine and triiodothyronine produced in the thyroid follicles are critically important for the normal growth and development and for the energy metabolism.
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Calcitonin produced in the interfollicular cells is involved in the control of plasma calcium.
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The steps in thyroid hormone synthesis, storage and secretion include:
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uptake of iodine by the follicle cells
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oxidation of iodine and iodination of tyrosine residues of thyroglobulin
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secretion of thyroid hormone
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Thyroid hormone is essential for the normal growth and development.
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Deficiency results in cretinism.
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They have a marked effect on the lipid, carbohydrate and protein metabolism.
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Both T3 and T4 are used to treat thyroid hormone deficiency
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Its absorption is influenced by the presence of food in the stomach, suralfate, iron and calcium.
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Enzyme inducers like phenytoin, rifampin, carbamazepine increase the metabolism
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Last modified: Thursday, 26 April 2012, 4:54 AM