Thyroid dysgenesis thyroid gland may be located anywhere along the path of the descent of the thyroid during its embryological development, although it is most commonly located at the base of the tongue, just posterior to the foramen cecum of the tongue. In this location, an aberrant or ectopic thyroid gland is known as a "lingual thyroid". If the thyroid fails to descend to even higher degree, then the resulting final resting point of the thyroid gland may be high in the neck, such as just below the hyoid bone. Parts of ectopic thyroid tissue ("accessory thyroid tissue") can also occur, and
Thyroid is the production of the iodine-containing thyroid hormones, triiodothyronine (T) and thyroxine (T) and the peptide hormone calcitonin. T is so named because it contains three atoms of iodine per molecule and T contains four atoms of iodine per molecule. The thyroid hormones have a wide range of effects on the human body. These include: After secretion, only a very small proportion of the thyroid hormones travel freely in the blood. Most are bound to thyroxine-binding globulin (about 70%), transthyretin (10%), and albumin (15%). Only the 0.03% of T and 0.3% of T traveling freely have hormonal activity. In addition,