Early Development 1 Flashcards
What makes a developmentally competent gamete?
They need to be able to migrate to the gonadal ridge, continue to proliferate (diploid) to make the reserve for male and females, oogonia and spermatogonia. they need support (granulosa or sertoli cells) and they need endocrine support.
What makes a developmentally competent gamete?
They need to be able to migrate to the gonadal ridge, continue to proliferate (diploid) to make the reserve for male and females, oogonia and spermatogonia. they need support (granulosa or sertoli cells) and they need endocrine support.
Development of ovaries vs testis at 8 weeks, 12 weeks and 16 weeks
sex specification occurs at 8 weeks, then sex discrimination of external genetalia at 12 weeks. at 16 weeks the testis have tubular cord structures and the ovary has follicle-like thingys.
When does a female aquire her eggs?
They are all aquired before birth. A bunch are lost to atresia.
What is the size of a human ovary, and the size of a non-pregnant uterus (in adults).
ovary: 3-5cm. uterus: 7cm x 4cm, or like a bit smaller than a bar of soap.
Where do these words fit into the ovarian cycle: oogonium, primary and secondary oocyte, granulosa cells, zona pellucida, theca cells, graafian follicle, cumulus oophorous, corpus luteum, corpus albicans
The oogonium is where you start- its enclosed in zona pelucida and enclosed in a follicle, then turns into the primary oocyte. the primary oocyte is surrounded by zona pellucida, outside of which are the granulosa cells (this is all the primary follicle). Theca cells eventually line the outside of the follicle. Soon, the antral space will develop, and a section of granulosa cells called the cumulus oophorous, along with the egg, will detach from the follicluar wall and “float” like an island in the antral cavity. The graffian follicle is the mature follicle, which (after ovulation) degenerates into the corpus luteum, and then the corpus albicans if implantation is not achieved.
what is menarche
beginning of ovarian cycling in people
what happens during the follicular phase of someoneundergoing infertility treatment?
Multiple graffian follicles
what happens during the follicular phase of someoneundergoing infertility treatment?
Multiple graffian follicles
What are the hormones even doing in the ovarian cycle (ya, you still dont know this one)
On day 1 of ovarian cycle, you get GnRH. This increases FSH and LH, and the follicle does its thing. The follicle is sneaky though, and releases some estrogen, which (AT LOW CONCENTRATIONS) causes negative feedback on the pituitary. you get less LH due to this. Also, weirdly enough, low levels of estrogen are what cause FSH release, so as estrogen increases LH drops off. After 10 ish days, that estrogen will be high enough to cause an LH spike! O V U L A T I O N. Estrogen drops. FSH spikes a teeny bit too as a side effect. now the corpus luteum starts releasing a bit of estrogen, inhibin, and progesterone. Inhibin stops FSH release (bcc we just ovulated and dont need it). Progesterone does - feedback on the hypothalamus, which decreases LH and FSH. The main thing, is that it stimulates endometrial growth. If there is no implantation, the corpus luteum degenerates and there is a drop in progesterone and estrogen. This causes endometrial shedding.
How does the combination BC pill actually work?
The progesterone doesnt allow FSH to stimulate follicles, and it also thickens cervical mucus. The estrogen at a constant level doesnt allow for that LH spike (no ovulation).
Primar vs secondary ovarian follicles
Secondary has the zona pellucida, the granulosa cells AND the thecal cells.
Whats the corona radiata? The mural granulosa cells?
corona radiata is basically the outer layer of the cumulus oophorous, and the mural granulosa cells are the ones by the edge of the follicle.
Where does spermatogenesis take place?
Spermatogenesis takes place adjacent to the basement membrane of the seminiferous tubules, and the mature ones are stored in the epididymis
When do spermatogonia develop into primary spermatocytes?
puberty
Spermiogenesis vs spermatogenesis
spermatids fully differentiate by way of spermiogenesis.
