That GnRH travels to the nearby pituitary, which secretes two hormones of its own - follicle stimulating hormone, or FSH, and luteinizing hormone, or LH.
But first it releases a final hormonal swan song — a bunch of progesterone, a little estrogen, and some inhibin — that together stop the release of FSH and LH.
In any case, the ovaries fail to respond to pituitary LH and FSH and which means that they don't release egg cells normally and produce less estrogen, progesterone, and androstenedione.
The body will respond by producing more follicle-stimulating hormone (FSH) and luteinizing hormone (LH) than normal, since these hormones stimulate estrogen secretion by the ovaries.
Meanwhile, the FSH and LH released from the anterior pituitary start to rise again, stimulating the next round of follicles, which begin to make estrogen.
In premature ovarian failure when estrogen levels are low the pituitary gland attempts to restore balance by increasing production of gonadotropins LH and FSH.
The LH gets to work on the oocyte that's been dormant inside the follicle, and triggers it to finally start dividing again — getting it to complete meiosis I and move on to metaphase II.
LH 开始作用于卵泡内休眠的卵母细胞,并触发最终再次开始分裂——让完成减数分裂 I 并进入中期 II。
Right after ovulation, while the LH levels are still high, the remains of the follicle turn into the corpus luteum, which is made up of luteinized granulosa and theca cells.
FSH acts on the granulosa cells, making the follicles grow and mature, as well as secrete estrogen while LH stimulates theca cells to secrete progesterone and small amounts of androstenedione, which is a precursor of testosterone.
This is a sex hormone that stimulates the anterior pituitary to release two more hormones: follicle-stimulating hormone — you'll often hear it called FSH — and luteinizing hormone, or LH.
The amount of GnRH can be mapped out like a wave over time, and the frequency and amplitude of the waves of GnRH determine how much FSH and LH get produced by the pituitary.