ovary Flashcards
what surrounds the highly vascular medulla
the cortex
what encapsulates the ovary and what is the outer surface lined with?
tunica alubiginea, lined by a single layer of cuboidal/ columnar cells
what is the tunica albuginea continous with?
the squamous cells of the mesovarium
what encloses the female germ cells
follicles in the cortex
where are the follicles in the cortex embedded?
embedded of the thick surrounding connective tissue of the stroma
what fills the rest of the cortex?
albicans and corpora lutea
what are the main components of the medulla
helicine arteries
what lies under the tunica albuginea?
primordial follice
the size and appearance of the primordial follicle
pale in size (25-30micrometers) and have a central primary oocyte
what envelops the primordial oocyte
follicular cells (squamous cells)
what seperates the follicular cells from the surrounding stroma
basal lamina
from primordial follicle to primary follicle
- increase in size
- secrete proteoglycan rish substance forming the ZONA PELLUCIDA
- follicular cells start to proliferate resulting in the formation of multilaminar layer the ZONA GRANULOSA
what is the inner layer of the endocrine secretory cells called?
theca interna
what is the outer layer of the endocrine secretory cells called?
theca externa surrounded by stromal cells
what happens as the follicle matures
moves towards the cortical zone
what happens to the zona granulosa in the secondary follicle?
proliferate and fluid filled cavities form between the cells
what does the irregular cavities result in? in the secondary folicle
the formation of the follicular antrum
what is the follicular antrum surrounded by?
stratified epithelium
what does the granulosa region show in the secondary follicle?
a thickened region called the cumulus oophorus containing the primary oocyte in its center.
what forms the corna radiata?
coloumnar granulosa cells attached to the oocyte
what happens to the graafian follicle?
- the follicular antrum increases in size
- follicle extends the full thickness of the ovarian cortex
what happens in the preovulatory stage?
proliferation of the granulosa cells slows down and cavities develop in the cumulus oophorus
what happens right before ovulation?
oocyte with its corona radiata detaches from the follicular wall and floats freely in the follicular fluid
function of the basal membrane in the graafian follicle
supports the outermost layer of the granulosa cells which separates the cells from separating them from the theca folliculi
shape and function of the cells that make the theca interna
- polygonal/ spindle shaped cells
- secrete steriods which contain lipid droplets in their cytoplasm
- fibroblast and collagen firbers can be observed
the theca externa
- contains layers of fibers of smooth muscle cells
- contains flattened fusiform connective tissue
- not very distinguishable
what happens after ovulation
follicular wall becomes folded and collapses, bleeding appears from the ruptures capillaries of the theca interna which forms a central blood clot
in the corpus luteum of menstration?
-the granulosa and theca interna cells increase in size
what originates from the granulosa cells? and what do they form?
granulosa lutein cells and form the main bulk of the corpus luteum
what originates from the theca interna? where are they located?
theca lutin cells, darker stained, and located at the periphery of the corpus lutuem
what happens to the connective tissue within the theca interna? in the corpus luteum?
strands on conn. tissue invades the avascular granulosa cell mass.
what happens to a central blood clot
it transforms into fibrous tissue due to the invasion of conn. tissue from the theca interna to the granulosa cell mass.
what happens if fertilization does not occur?
- the corpus letuem undergoes involution, fatty
- degenration within the lutein cells
- macophages engulf the cellular debris
- connective tissue replaces the endocrine cells
- fibrous cell mass atrophies
- hyalin substance accumulates and forms a scar like
- strcture called the CORPUS ALBICANS
what is the Corpus albicans?
a scar like structure due to fertalization not happening and is mainly due to the degenration of the substance within the lutein cells
what happens in follicular atresia?
oocyte nucleus becomes eccentric and coarsly granular then pyknotic
what is the first sign of degeneration of a follicle?
loosening and disorganization of the granulosa cells
followed by invasion of granulosa layer by macrophages and vascular connective tissue cells
what happens to the zona pullucida, and what does it form?
it thickens and forms a layer of hyalin substance in the center of the atretic follicle.
what happens to the theca interna cells of the atretic follicle?
proliferate forming radial cords that display features and secrete steriod hormones
what are the follicles of different developmental stages surrounded by?
dense stroma made out of fibroblast-like or mesenchymal cells located in the cortex
how long does growth from primordial to antral stage take?
85 days, the last follicular growth occurs in the 15 day follicular phase of the menstrual cycle
