What hormones are produced by the thyroid gland?

The thyroid gland, an endocrine gland in the neck, secretes three hormones:

1. Thyroxine (T4): T4 is the primary hormone produced by the thyroid gland. It is responsible for regulating the body's metabolic rate, energy production, and development.

2. Triiodothyronine (T3): T3 is also involved in regulating metabolism and energy production. While it is produced in smaller amounts compared to T4, it is more biologically active. T3 is mostly produced through the conversion of T4 into T3 in various tissues throughout the body.

3. Calcitonin: Calcitonin plays a role in regulating calcium levels in the bloodstream. It opposes the actions of parathyroid hormone (PTH), lowering blood calcium levels by promoting the deposition of calcium in bones and inhibiting its release from bone tissue. This is important for maintaining calcium homeostasis and ensuring the proper functioning of the skeletal system and calcium metabolism.

In addition to these primary hormones, the thyroid gland also produces a protein called thyroglobulin, which serves as a storage form of thyroid hormones within the gland.