Understanding the “hypothalamic-pituitary-thyroid” axis
The thyroid is an important endocrine gland in our body, and its function is regulated from the top down (below), which is called the “hypothalamic-pituitary-thyroid” axis.
The hypothalamus, which is located in our brain, is the “command” that secretes a hormone called thyrotropin-releasing hormone (TRH), which regulates It secretes a hormone called thyrotropin-releasing hormone (TRH), which regulates the secretion of thyroid stimulating hormone (TSH) by its “subordinate” pituitary gland, which in turn directs its “subordinate” thyroid gland to secrete thyroid hormone (TSH). “The thyroid gland secretes thyroid hormone.
But the thyroid gland is not just “passive”; if the TSH is “biased” in its commands, resulting in inappropriate amounts of thyroid hormone production, it will also “correct” itself from the bottom up. “If there is too much thyroid hormone in the blood, it will “feed back” to the pituitary gland, asking it to reduce TSH secretion and give the thyroid gland a “break”; if there is too little, it will inform the “pituitary gland “If too little is produced, the pituitary gland is told to produce more TSH, “spurring” the thyroid to work harder. This is called “negative feedback regulation” in medicine.
“Endocrine disruption”, is it related to thyroid cancer?
It is thought that the more active this “axis” is, the more active the thyroid gland becomes (e.g., hyperthyroidism) and the more thyroid hormones are produced, which may increase the incidence of thyroid cancer]. It has also been suggested that TSH levels may be associated with the development of thyroid cancer, and that the incidence of differentiated thyroid cancer increases with TSH levels. However, more evidence is needed to support all of these ideas.
In fact, the relationship between various hormone levels on this “axis” and thyroid cancer is uncertain and needs further study.
Co-written by Dr. Kai Guo, Cancer Hospital of Fudan University
.