B8.025 - Ovary Histology/Physiology Flashcards
function of the ovary
produce female germ cells, ova
to synthesize and secrete sreroid and peptide hormones
what makes up the medulla of the ovary
vasculature
lymphatics
nerves
what are components of the cortex of the ovary
follicles containing oocytes at multiple stages of development
corpora lutea at various stages of function and regression
stages of folliculogenesis
primordial primary preantral antral graafian
what is folliculogenesis
a growth and development of immature follicles and oocytes to mature follicles and ova capable of undergoing ovulation and fertilization
zona pellucida
composed of 4 glycoproteins ZP1-4, produced/secreted by oocyte, has a sperm binding receptor, acrosome reaction occurs here, block to polyspermy, protection for embryo, tranzonal interaction between granulosa and oocyte
what happens with the premordial follicle
granulos cells proliferate into multiple layers, Theca differentiates
what happens with the antral follicle
antrum forms, first as several small pockets that coalesce into one
follicular fluid forms, theca differentiates into interna/externa
granulosa continues to proliferate
increased estradiol production
what happens with graafian follicle
granulosa continues to proliferate, increasing follicle diameter, increasing blood supply, oocyte pushed to one side
what happens in ovulation
surge of LH
basement membrane breaksdown, blood vessel penetration, oocyte moves to center of follicle, cumulus expansion, oocyte resumes meiosis, granulosa cell differentiation, enzyme production
steps of oocyte resuming meiosis
completion of meiosis 1
1st polar body
oocyte arrests in metaphase 2
steps of granulosa cell differentiation
aromatase off
estradiol to progesterone
proliferation stops
enzyme production in ovulation
histamine –> hyperemia
PA = breakdown tunica albuginea
steps leading up to oocyte release
increasing pressure
proteolytic activity
oocyte release
describe the process of establishment of oocyte complement
during development of the ovary the primordial germ cells migrate from yolk sac to gonadal ridge regulated by c kit
when in oocyte development does the cycle arrest
prophase 1 of meiosis
describe the development of the oocyte complement
- initially oocytes are organized in nests
- some oocytes undergo apoptosis
- individual oocytes with associated granulosa is left (primordial follicle)
how is primordial follicle formation regulated
in part by transcription factors, growth factors, meiotic proteins like CAV1. NGF, DMCI
when does menopause occur
when oocytes run out
what is the biological checkpoint controlling female reproductive potential
primordial follicle entry into the growing pool
how long does development of the follicle take
3 phases:
1 - preantral growth: several months (gonadotropin independent)
2 - tonic growth: 2+ months (gonadotropin responsive)
3 - exponential growth - 21 days (gonadotropin dependent)
