What are thyroids? Describe the disorders of thyroids hor¬mones.
The thyroid gland is situated in the neck close to the trachea in human beings. It consists of two elongated oval lobes joined together by a narrow band called ISTHMUS. It highly vascular organ and contains many- spherical or oval sac-like follicles. Cells of the follicle secrete jelly-like semi-fluid called Colloid of Thyroid stored in the lumen of the follicle. This contains iodinated forms of an amino acid called THYRONINE. When required, two thyroid hormones, THYROXINE, and TRIIODOTHYRONINE are released from the colloid to the blood. Disorders: Failure of the thyroid from infancy or childhood causes a disease called cretinism. In it, there is slow body growth and mental development. There is also a low metabolic rate. The deficiency of thyroid hormones in adults produces Myxedema. The patient shows a puffy appearance and lacks intelligence, lateness, and initiative. There is also a low metabolic rate. The deficiency of iodine produces enlargement of thyroids causing Iodine Deficiency to Goitre. Some thyroid enlargement is accompanied by a bulging of the eyeball. The disease is called Grave’s Disease or Exophthalami Goitre. The excessive amount of thyroid is secreted. ,
