Thyroxin, also commonly spelled as thyroxine, is a hormone produced by the thyroid gland, an endocrine gland situated in the neck region. It is one of the two major hormones secreted by the thyroid gland, with the other being triiodothyronine (T3). Thyroxin plays a vital role in regulating the body's metabolism, growth, and development.
The production of thyroxin is controlled by the hypothalamus and the pituitary gland. When the levels of thyroxin in the bloodstream are low, the hypothalamus releases thyrotropin-releasing hormone (TRH), which triggers the pituitary gland to release thyroid-stimulating hormone (TSH). This hormone then stimulates the thyroid gland to produce and release thyroxin.
Thyroxin acts on many tissues and organs throughout the body, binding to specific receptors located within cells. It influences the rate at which cells convert oxygen and calories into energy, known as the basal metabolic rate. Consequently, thyroxin affects a wide range of bodily functions, including heart rate, body temperature, weight management, digestion, and brain development.
When the production of thyroxin is disrupted, it can lead to various health conditions. Hypothyroidism occurs when thyroxin levels are insufficient, resulting in fatigue, weight gain, depression, and slowed metabolism. On the other hand, hyperthyroidism arises from excessive thyroxin production, leading to symptoms such as weight loss, rapid heart rate, anxiety, and elevated body temperature.
Therapies for thyroid disorders often involve regulating the levels of thyroxin. Synthetic forms of thyroxin, like levothyroxine, may be prescribed to patients with an underactive thyroid (hypothyroidism)
