NBME 24 Answers ↦
Who can explain, the 12-y boy with stanner stage 2？？
I thought it should be stage 3....
I also picked decreased inhibin.
may be it was one of the "experimental questions", which are not even counted on the real exam
Inceased FSH will lead to spermatogenesis and spermiogenesis NOT Increase in Testosterone which is causing increased Height of this pt
Inhibin B only has negative feeback on FSH not GnRH. see the diagram on the topic of semineferous tubules in FA. Testosterone has a negative feedback on BOTH LH and GnRH
Kind of like how nocturnal pulsatile GNRH release occurs during sleep to stimulate growth (FA page327), the same thing happens for puberty. Pg 325 in FA, "pulsatile GnRH leads to puberty and fertility." It doesn't explicitly state during sleep, but pulsatile release of GnRH leading to pulsatile release of LH and FSH will lead to puberty. Puberty starts in the brain, its onset really has nothing to do with decreased inhibin levels which happens in the testes. hope that makes sense!
From what I understand, inhibin is only released by granulosa cells when FSH levels are high. This is a boy. Next off, this question is about puberty, which is due to pulsatile GnRH leading to large amounts of LH and FSH, leading to large amounts of dihydrotestosterone (males) and estradiol (females), and eventually secondary characteristics of puberty. The increased pulse of estrogen and testosterone leads to GH release, which is metabolized into IGF-1 in the liver. This leads to long bone growth from what I understand, which is not much.
@sars inhibin B is also released by sertoli cells in males and will feedback to inhibit FSH release, its not just a female thing. Also, there is actually an inhibin B pubertal surge in both females and males that corresponds to maturation of the granulosa and sertoli cells, respectively. Hormones are wack. https://pubmed.ncbi.nlm.nih.gov/15319819/
Costanzo says " One of the earliest events of puberty is the appearance of large nocturnal pulses of LH during REM sleep. "
also, I am aware of how late this answwer is :P