The primary function of the thyroid gland is to produce hormones that control physical and mental growth, metabolism, and a wide range of other physiological functions.
The thyroid is a gland located in the neck, in front and around the larynx and trachea. It weighs less than an ounce and is comprised of halves known as lobes, which are connected by a narrow band of tissue called the isthmus.
The thyroid gland produces the thyroid hormones known as triiodothyronine (T3) and thyroxine (T4). To produce these two hormones, the gland combines iodine, obtained from one’s diet, and the amino acid tyrosine.
T3 and T4 are released into the bloodstream to be transported to different parts of the body. These hormones influence how the brain develops during childhood, and they also serve an important role in regulating metabolism in adulthood.
Is there anything thyroid hormones can’t do? Well, they can’t cross the cell membrane, so they need specific hormone receptors to trigger a reaction within the cell and start the production of several important proteins.
With these proteins, the cells can start a variety of processes including cell reproduction, free radical scavenging and antioxidant production, insulin secretion, and promoting insulin sensitivity. Due to these effects, thyroid hormones are crucial in maintaining the healthy function of the digestive, nervous, muscular, and circulatory systems.
Another function of the thyroid hormones is the regulation of the mitochondria. T3 and T4 do this by controlling how much oxygen the mitochondria consumes, which is a vital step in ATP production.
Since the mitochondria are the primary producer of adenosine triphosphate (ATP), thyroid hormones play a crucial role in making sure cells get the energy they need for various physiological functions.
The thyroid gland is regulated by the pituitary gland. Also known as hypophisis this peanut-sized gland is found at the base of the brain and produces thyroid stimulating hormone (TSH).
TSH is produced when the pituitary gland detects that the T3 and T4 hormones in the bloodstream are too low. And when these hormones are too abundant, the pituitary gland stops TSH production.
Aside from detecting thyroid hormones in the blood, the pituitary gland also receives input from the hypothalamus. The hypothalamus determines the necessary levels of thyroid hormones based on the various needs of cells in different parts of the body.
The hypothalamus and the pituitary gland play a very active role in regulating the thyroid. Having too little or too much of the thyroid hormones can be harmful.
Gaining weight, feeling cold (even though it actually isn’t), and having dry skin are signs that your thyroid might be underactive. This state is called hypothyroidism.
On the other hand, if you’re experiencing weight loss, high heart rate, hot flashes, and high anxiety, your thyroid might be producing too much thyroid hormone. In this case, you might have hyperthyroidism.
Keeping your thyroid healthy is important as it has immense overall benefits for your health. With lower levels of thyroid hormone, luteinizing hormone (LH) levels are decreased, which results in decreased testosterone production.
This relation also goes the other way around, meaning low testosterone can result in low thyroid gland activity. And so, when any of these hormones aren’t kept at optimal levels, various risks to male health will arise.