When estrogen begins to raise hGH levles, when is that?

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johnwandering

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In female reproduction, there is a point where a huge excess of estrogen begins to cause a positive feedback of hGH (while before it was negative feedback).

I was wondering if this was during the follicular phase or ovulation (seems to be right in between. Kaplan seems to say ovulation, EK says before ovulation)

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I would say go with kaplan?

EK has the absolute Worst section on menstration lve ever seen. Its barely comprehendable and they put in a lot of useless informaion you dont need.

It should be during ovulation.
 
In female reproduction, there is a point where a huge excess of estrogen begins to cause a positive feedback of hGH (while before it was negative feedback).

I was wondering if this was during the follicular phase or ovulation (seems to be right in between. Kaplan seems to say ovulation, EK says before ovulation)


Are you talking about LH?
 
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GnRH is inhibited by both progesterone and estrogen. If fertilzation occurs the corpus luteum is maintained and continues to produce estrogen and progesterone, which continues the negative feedback on GnRH, eventually placenta takes over for corpus luteum. If fertilzation does not occur, corpus luteum atrophies, estrogen and progesterone levels decline, removing the block on GnRH and endometrium sloughs off.
 
Low levels of estrogen inhibits release of GnRH (NOT GH) from the Hypothalamus via adrenergic neuron upregulation and stimulation. This causes inhibitory modulation of LH, but the growing size of the follicle and granulosa cells cause them to produce more estrogen than can be inhibited by low LH.

At a certain level of estrogen, high levels of estrogen stimulates release of GnRH from the Hypothalamus via NPY neuron upregulation and stimulation. This causes a positive feedback loop that results in the LH surge.
 
Low levels of estrogen inhibits release of GnRH (NOT GH) from the Hypothalamus via adrenergic neuron upregulation and stimulation. This causes inhibitory modulation of LH, but the growing size of the follicle and granulosa cells cause them to produce more estrogen than can be inhibited by low LH.

At a certain level of estrogen, high levels of estrogen stimulates release of GnRH from the Hypothalamus via NPY neuron upregulation and stimulation. This causes a positive feedback loop that results in the LH surge.

Do you know why progesterone in birth control pills thins the endometrium? I learned in A&P that progesterone is what is mainly responsible for endometrial growth in preparation for an embryo.
 
The simpler way to memorize it is that estrogen grows the endometrium while progesterone maintains it. Progesterone is inhibitory to GnRH release from Hyth and thus inhibits release of estrogens.
 
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