The thyroid is one of the largest endocrine glands in the corpse. This gland is found in the neck inferior to (below) the mouth and at approximately the same raze as the cricoid gristle. The thyroid controls how post-haste the body burns energy, makes proteins, and how sensitive the body should have being to other hormones. The thyroid participates in these processes through producing thyroid hormones, principally thyroxine and triiodothyronine. These hormones put in order the asperse of metabolism and affect the growth and rate of function of many other systems in the body. Iodine is an essential component of both T3 and T4. The thyroid also produces the hormone calcitonin, which plays a role in calcium homeostasis. The thyroid is controlled by the hypothalamus and pituitary. The gland gets its name from the Greek word with regard to 'shield', after its shape, a double-lobed structure. Hyperthyroidism (overactive thyroid) and hypothyroidism (underactive thyroid) are the most common problems of the thyroid gland. Specialists are called thyroidologists.