Female Reproductive Histology Flashcards
how does the histology of the ovaries change throughout the reproductive years?
Before puberty, ovaries have a smooth surface
Throughout the reproductive years, the ovaries becomes scarred and irregular due to repeated ovulations
In post-menopause, the ovaries are a fourth of their original size
when during embryogenesis do the germ cells migrate from the yolk sac to the gonads?
week 4
female primordial germ cells
oogonia - migrate to the ovarian cortex during embryonic week 4 and undergo mitotic proliferation by the 5th month of gestation
the ______ ligament contains the ovarian vessels
suspensory ovarian ligament
what is found in the cortex vs medulla of the ovary?
cortex: follicles (various stages of development, mostly primordial) + stroma (vascular and cellular)
medulla: loose CT, vessels, nerves
how do primordial follicles appear histologically?
primary oocyte - large cell in prophase of meiosis I, euchromatic nucleus with prominent nucleolus
follicular/granulosa cells - single layer of flat cells surrounding oocyte
how do primary follicles appear histologically? name the included structures (6)
from inside to outside:
1. primary oocyte
2. zona pellucida (glycoprotein, made by oocyte) - bright circle
3. follicular/granulosa cells - cuboidal, connected to oocyte via cell processes and gap junctions
4. basement membrane
5. stromal theca cells interna - steroid-producing with lipid droplets
6. stromal theca cells externa - connective tissue, no endocrine function
how does a secondary/ Antral follicle appear histologically?
from inside to outside:
1. primary oocyte
2. zona pellucida - bright ring
3. follicular/granulosa cells (6-12 layers)
4. antrum - fluid-filled cavity with hormones from glomerulosa cells
5. basement membrane
6. theca interna - LH-induced secretion of androstenedione
7. theca externa - blends with stroma
how do mature/Graafian follicles appear historically?
from inside to outside:
1. secondary oocyte (if this oocyte is undergoing ovulation)
2. zona pellucida
3. granulosa cells forming cumulus oophorus (“hill”) and corona radiata (“crown”)
4. very large antral cavity
5. basement membrane
6. theca interna
7. theca externa
what changes occur to a mature/Graafian follicle if the follicle undergoes ovulation?
the primary oocyte continues meiosis up to metaphase II to become a secondary oocyte + polar body
the oocyte and corona radiata are released
meiosis II is completed if fertilization occurs
what are the distinctive histological features of primordial, primary, secondary/Antral, and mature/Graafian ovarian follicles?
primordial - single layer of flattened follicular/granulosa cells
primary - 1+ layers of cuboidal follicular cells and zona pellucida appears
secondary/Antral - antral cavity appears
mature/Graafian - largest follicle with very large antral cavity
how can atretic follicles (degenerating) be identified histologically?
thick, folded basement membrane/ zona pellucida + invading macrophages
what is an ovarian stigma?
stigma aka macula pellucida: area of the ovarian surface (tunica albuginea) where the Graafian follicle bursts through during ovulation and releases the ovum
proteases from fibroblast degrade connective tissue
fill in the blanks regarding the development of the ovarian corpora (“bodies”) during the luteal phase: ovulated graafian (mature) follicle —> ________ —> __________ —> _________
ovulated graafian (mature) follicle —> corpus hemorrhagicum (“bleeding body”) —> corpus luteum (“yellow body”) —> corpus albicans (“white body’)
how do granulosa vs theca cells appear histologically in the corpus luteum?
granulosa - increase in size to become large/round/pale, centrally located, majority of corpus luteum
theca - smaller and darker, peripherally located in folds