| thyroid foramen | An opening occasionally existing in one or both of the plates of the thyroid cartilage. Synonym: foramen thyroideum. (05 Mar 2000) |
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| thyroid gland | A butterfly-shaped endocrine gland in the neck that is found on both sides of the trachea windpipe). It secretes the hormone thyroxine which controls the rate of metabolism. (27 Sep 1997) |
| thyroid gland, desiccated | The cleaned, dried, and powdered thyroid gland, previously deprived of connective tissue and fat, obtained from domesticated animals that are used for food by man, containing 0.17-0.23% of iodine in thyroid combination, occurring as a yellowish to buff-coloured amorphous powder. It was formerly used as a source of thyroid hormones in the treatment of hypothyroidism. (12 Dec 1998) |
| thyroid hormone | <endocrinology> Thyroxine and tri iodothyronine are hormones secreted by the thyroid gland in vertebrates. These iodinated aromatic amino acid compounds influence growth and metabolism and, in amphibia, metamorphosis. The hormone calcitonin which has hypocalcaemic effects is also of thyroid origin but is not usually classed with thyroxine and tri iodothyronine as a thyroid hormone. (18 Nov 1997) |
| thyroid hormone aminotransferase | <enzyme> Chemical name: 3,5-dinitrotyrosine aminotransferase Registry number: EC 2.6.1.26 Synonym: triiodothyrone aminotransferase, triiodothyronine aminotransferase (26 Jun 1999) |
| thyroid hormone resistance syndrome | <syndrome> An inherited syndrome of peripheral resistance to thyroid hormones, transmitted as an autosomal recessive trait, characterised by increased serum concentrations of thyroxine and triiodothyronine, increased thyroid hormone binding ratio, and normal to slightly increased thyroid-stimulating hormone and its response to thyrotropin-releasing hormone. The affected persons are euthyroid to slightly hypothyroid. The absence of hypermetabolism and the presence of possible hypothyroidism indicate the existence of partial resistance to the peripheral action of thyroid hormone. (12 Dec 1998) |
| thyroid hormones | Chemical substances made by the thyroid gland which is located in the front of the neck. The thyroid gland uses iodine to make thyroid hormones. Thyroid hormones are essential for the function of every cell in the body. They help regulate growth and the rate of chemical reactions (metabolism) in the body. The two most important thyroid hormones are thyroxine (t4) and triiodothyronine (T3). (12 Dec 1998) |
| thyroid ima artery | <anatomy, artery> An inconstant artery; origin, arch of aorta or brachiocephalic artery; distribution, thyroid gland. Synonym: arteria thyroidea ima, lowest thyroid artery, Neubauer's artery. (05 Mar 2000) |
| thyroid imaging | <radiology> Tc-99m pertechnetate 6 mCi, I-123 sodium iodide 200 - 400 uCi PO (12 Dec 1998) |
| thyroid insufficiency | Subnormal secretion of hormones by the thyroid gland. See: hypothyroidism. (05 Mar 2000) |
| thyroid lymph nodes | Nodes of the anterior deep cervical group located around the thyroid gland; they drain into the lateral deep cervical group. Synonym: nodi lymphatici thyroidei. (05 Mar 2000) |
| thyroid nodule | A small circumscribed mass of differentiated tissue associated with the thyroid gland. It can be pathogenic or non-pathogenic. The growth of nodules can lead to a condition of goiter, nodular. most nodules appear between the ages of 30 and 50 years and most are benign. (12 Dec 1998) |
| thyroid receptor antibody | A test that measures the amount of an antibody (thyroid stimulating antibody) which is directed against a receptor for TSH on the thyroid gland. This antibody acts like TSH and stimulates the thyroid to produce excessive amounts of thyroid hormone. The presence of this antibody generally indicates Grave's disease (hyperthyroidism). (27 Sep 1997) |
| thyroid releasing hormone | <endocrinology> Thyroid releasing hormone (TRH) is a byproduct of the hypothalamus and serves to stimulate the pituitary gland to produce thyroid stimulating hormone (TSH). TRH is produced by the hypothalamus when thyroid hormone (T3 and T4) blood levels are low. (27 Sep 1997) |
| thyroid scan | A picture taken of the thyroid gland after radioactive iodine is taken by mouth. (12 Dec 1998) |
| hot thyroid nodule | <radiology> Almost always hyperfunctioning adenoma, vast majority benign, up to 50% are autonomous see also: thyroid carcinoma, cold thyroid nodule (12 Dec 1998) |
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| pyramidal lobe of thyroid gland | <anatomy> An inconstant narrow lobe of the thyroid gland that arises from the upper border of the isthmus and extends upward, sometimes as far as the hyoid bone; it marks the point of continuity with the thyroglossal duct. Synonym: lobus pyramidalis glandulae thyroideae, Lallouette's pyramid, Morgagni's appendix, pyramid of thyroid. (05 Mar 2000) |
| pyramid of thyroid | <anatomy> An inconstant narrow lobe of the thyroid gland that arises from the upper border of the isthmus and extends upward, sometimes as far as the hyoid bone; it marks the point of continuity with the thyroglossal duct. Synonym: lobus pyramidalis glandulae thyroideae, Lallouette's pyramid, Morgagni's appendix, pyramid of thyroid. (05 Mar 2000) |
| sheath of thyroid gland | Covering of the thyroid gland external to its capsule formed by a splitting of the pretracheal layer of deep cervical fascia at the gland's posterior border; the anterior lamina covers the gland anterolaterally, attaching to the arch of the cricoid cartilage superior to the isthmus of the gland (causing it to move with the trachea during elevation/depression of the larynx); the posterior lamina passes posterior to the oesophagus to blend with the buccopharyngeal fascia; inferiorly, the sheath extends along the inferior thyroid veins to open into the superior mediastinum (hence, expansion of the thyroid, as by goiter, can take this direction). (05 Mar 2000) |
| sternocleidomastoid branch of superior thyroid artery | <anatomy, artery> Branch of superior thyroid artery to sternocleidomastoid muscle. Synonym: ramus sternocleidomastoideus arteriae thyroideae superioris. (05 Mar 2000) |
| stroma of thyroid gland | The connective tissue that supports the lobules and follicles of the thyroid gland. Synonym: stroma glandulae thyroideae. (05 Mar 2000) |
| superior horn of thyroid cartilage | One of the pair of upward prolongations from the thyroid cartilage to which the lateral hyothyroid ligament attaches. Synonym: cornu superius cartilaginis thyroideae. (05 Mar 2000) |
| superior thyroid artery | <anatomy, artery> Origin, external carotid; branches, infrahyoid, superior laryngeal, sternocleidomastoid, cricothyroid, and two terminal branches. Synonym: arteria thyroidea superior. (05 Mar 2000) |
| superior thyroid notch | A deep notch in the middle of the upper border of the thyroid cartilage. Synonym: incisura thyroidea superior. (05 Mar 2000) |
| superior thyroid plexus | An autonomic plexus on the artery of the same name, derived from the external carotid plexus. Synonym: plexus thyroideus superior. (05 Mar 2000) |
| superior thyroid tubercle | A blunt projection on the lamina of the thyroid cartilage on either side at the superior end of the oblique line. Synonym: tuberculum thyroideum superius. (05 Mar 2000) |
| superior thyroid vein | <anatomy, vein> Receives blood from the upper part of the thyroid gland and larynx, accompanies the artery of the same name, and empties into the internal jugular vein. Synonym: vena thyroidea superior. (05 Mar 2000) |
| suspensory ligament of thyroid gland | One of several fibrous bands which pass from the sheath of the thyroid gland to the thyroid and cricoid cartilages. (05 Mar 2000) |
| discordant thyroid nodule | <radiology> Hot on Tc-99m pertechnetate, cold on I-123 or I-131, indicates trapping, but no organification, same work-up as cold nodule (12 Dec 1998) |
| immunoglobulins, thyroid-stimulating | Autoantibodies that bind to the thyroid-stimulating hormone (tsh) receptor (receptors, thyrotropin) on thyroid epithelial cells. The autoantibodies mimic tsh causing an unregulated production of thyroid hormones characteristic of graves' disease. (12 Dec 1998) |