What's a Hormone?
Posted on July 21, 2011
And how do they help us ovulate? Hormones are chemicals that are made in one part of the body and act in another part of the body. For example, estrogen, our favorite hormone, is made in the ovaries and acts in the uterus, bones and other areas of the body. The hormone estrogen is stimulated by a different hormone, follicle stimulating hormone (FSH), which is made in the pituitary gland, a gland at the base of the brain. So the FSH hormone travels from the pituitary, through the bloodstream, to the ovaries and makes the follicle grow. It's the follicle that makes estrogen. And there's more. There's another hormone that starts the whole thing off, and it's called GnRH. This stands for gonadotropin releasing hormone. This is made in the brain (the hypothalamus to be precise). Just to review: The hormone GnRH comes from the brain to the pituitary through the blood stream. In the pituitary gland, GnRH stimulates FSH, which in turn travels to the ovary to stimulate the follicle to grow, and this produces estrogen.
We can use the thyroid system as another example. The hypothalamus makes TRH, which goes through the bloodstream to the pituitary gland to stimulate Thyroid Stimulating Hormone (TSH). TSH goes to the thyroid gland to make the thyroid hormone.