Thyroid Gland

A gland at the front of the neck lying just under the voice box, composed of two lobes attached by a narrow bridge called an isthmus that lies across the front of the trachea. The thyroid gland is the largest gland completely devoted to the endocrine system. It produces the following hormones:

Thyroxine and Triiodothyronine regulate energy metabolism and are essential for growth.
Calcitonin encourages calcium deposition in bone and controls blood calcium levels.