Thyroid Gland Location and Thyroid Dysfunction Disorders

Where is thyroid gland located and its function?

Thyroid is a butterfly shaped organ located in front of the neck, just below the voice box. It consists of two lobes, one on each side of the windpipe and is one of the largest endocrine glands in our body. In a normal adult, the thyroid gland weighs 15 to 25 grams. Just like every other organ in our body, thyroid gland has a specific function and role to play; infact, it is known to function even before birth. Thyroid gland functions to regulate the metabolism of our body by producing hormone that facilitate energy production.

The Facts behind the Gland
The thyroid gland is a component of the endocrine system that is, it produces hormones that are released into circulation. These hormones then travel to different cells and tissues in the body, where they play a wide variety of roles, primarily associated with cellular metabolism. Though first christened in 1656 by Thomas Wharton, the disorders of the thyroid especially its enlargement causing neck swelling, have been known long before then. It is surprising then, to know that the first successful isolation of a thyroid hormone and its identification was only done in 1914 by Kendall and Osterberg. They named it "Thyroxine", which today, is also colloquially called as T4 (thyroxine). Since then, we have developed our understanding of thyroid hormones, their functions in the body as well as disease conditions associated with thyroid gland and its hormones. The thyroid gland is located on the front part of the neck below the thyroid cartilage (Adam's apple) and releases two hormones triiodothyronine (triiodothyronine (T3)) and thyroxine (T4). These are iodine-containing hormones, among which T4 is the main hormone. At the site of action, i.e., inside the cells, one iodine is removed, leading to the formation of T3.

Thyroid hormones are important for regulating metabolic processes. These are processes that are responsible for energy production in the cell, as well as the formation and breakdown of proteins, LDL-bad cholesterol, carbohydrates and nucleic acids. These hormones are synthesized by thyroid follicular cells from thyroglobulin and stored in the thyroid follicle. The synthesis and release of thyroid hormones is stimulated by another hormone produced by the pituitary, called thyroid stimulating hormone (Thyroid Stimulating Hormone (TSH)), which acts like a regulating switch, turning on thyroid function when required and turning it off when not.

Mastermind behind many Functions
Thyroid hormones carry out a large number of functions in the body. Some of these include:
Metabolism Normal growth and development requires Metabolic processes that generate energy for the cells to utilize. These metabolic processes also provide the biomolecules that are required by the cells. Basal metabolic rate (BMR) is a unique rate at which the body expends energy at rest. Thyroid hormones play a role in stimulating BMR by increasing the breakdown of ATP molecules which results in the generation of energy. It also stimulates the pathways that involve breakdown and synthesis of carbohydrates, fats and liver.
Maintaining body temperature Maintaining body temperature requires generation of heat continuously, with more heat produced on exposure to cold, after eating or after energy expenditure. Thyroid hormones are required for the maintenance of core body temperature.
Regulation of body weight As thyroid hormones are required for regulation of fat metabolism, cholesterol synthesis and transport as well as breakdown into bile, thyroid hormones indirectly do impact body weight. These hormones stimulate breakdown of lipids directly, reducing triglycerides and LDL-bad cholesterol (including LDL) levels.