The thyroid, which is situated just below the larynx, is a gland of the body that performs a function that is likened to that of feedback. Its function of regulating the metabolism of the body is one that is totally depended upon by every cell that makes up the human body.
In order to perform this function of regulating the body’s metabolism, the thyroid gland absorbs the iodine contained in the food we eat and convert it to thyroid hormones. It is these thyroid hormones that work as the mechanics that regulate the metabolism of the body.
Two thyroid hormones, thyroxine (T4) and triiodothyronine (T3) are what the thyroid gland produces from the iodine extracted from our foods. The production of the two hormones is achieved by the thyroid gland by means of the combination of the iodine extracted from food with amino acid tyrosine.
Regulation of the body’s metabolism will then be achieved when the produced hormones, T3 and T4 are released and transported throughout the body. A normal thyroid gland produces around eighty percent (80%) T4 and twenty percent (20%) T3, but as lower in quantity the T3 produced are in proportion to T4, T3 has about four times the strength of T4.
The Collaborators Of The Thyroid Gland
The thyroid gland works under the control of the body’s pituitary gland. The pituitary gland is a small gland that is no more than the size of a peanut. It is located at the lower part of the brain. The pituitary gland is the organ of the body that watches the level of T3 and T4 present in the body.
At any point in time when the thyroid hormones T3 and T4 drops below the required, the pituitary gland starts the rescue operation of restoring the status quo by producing Thyroid Stimulating Hormones (TSH), which works on the thyroid gland by stimulating it to produce more T3 and T4.
This stimulation work done on the thyroid gland spurs it into action and it begins the secretion of T3 and T4, and this makes the blood levels to be raised. On sensing this situation, the pituitary gland steps in and the production of TSH will be reduced.
Does The Pituitary Gland Work Alone?
No, the pituitary gland works in collaboration with another gland before it can effectively watch the level of the thyroid hormones. The pituitary collaborating gland is called hypothalamus. The hypothalamus it is that tells the pituitary gland to stimulate the pituitary gland to release TSH. The hypothalamus is part of the human brain.
Let us close this discussion with this imagination; the hypothalamus is a person, the pituitary gland is a thermostat, the thyroid gland is a furnace and the thyroid hormones are heat. When heat gets to the thermostat, the thermostat gets turned off by the person, and as the room cools down (when the level of the thyroid hormone drops) the thermostat is turned on again by the person and more heat is produced.