NSE 22A/B Chapter Notes - Chapter 50, 51, 61: Toxic Multinodular Goitre, Medullary Thyroid Cancer, Papillary Thyroid Cancer
31 Jan 2016
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Document Summary
It consists of two encapsulated lateral lobes connected by a narrow isthmus. Located in the anterior portion of the neck, in front of the trachea. Regulated by tsh from the anterior pituitary. Major function -> production, storage, and release of the thyroid hormones. Three hormones produced and secreted by the thyroid gland: thyroxine, Case study 2 triiodothyronine & calcitonin: thyroxine [t4] & tri-iodothyronine [t3] Account for 90% of thyroid hormone produced by the thyroid gland. T3 is more potent and has greater metabolic effects. 20% of circulating t3 is secreted directly by the thyroid gland, and the remainder is obtained by peripheral conversion of t4. Iodine is necessary for the synthesis of thyroid hormones t4 and t3 affect metabolic rate, calorie requirements, oxygen consumption, carbohydrate and lipid metabolism, growth and development, brain function, and nervous system activity. More than 99% of thyroid hormones are bound to plasma proteins, especially t4-binding globulin synthesized by the liver.
