Female Repro Flashcards
Functions (5 of them)
production of ova
secretion of hormones
transport of male and female gametes for fertilization
protection and nourishment of the developing embryo and fetus
parturition
Ovary function
endocrine (hormones, estrogens and progesterone)
exocrine (gametes - the ova)
Cortex structure - surface epithelium
cuboidal - squamous, covered/continuous with peritoneum
Cortex structure - tunica albuginea
under surface epithelium
dense irregular connective tissue
Cortex structure - interstitial endocrine cells
carnivores only
large, lipid-laden cells
Originate from degenerating components of follicle wall
may secrete estrogen
Cortex structures - cortical cords
bitch only short tubules outer cortex no known function likely come from gonadal cords
Cortex structures - follicles
contain ova
are at various stages of development
surrounded by dense capillary networks
Structure Medulla
in center; surrounded by cortex
large vessel, nerves, some embryonic remnants (rete ovarii or medullary cords)
Structure - Hilus
region of entry/exit for nerves and vessels
nerves (symp. nonmyelinated) terminate on vessel walls (vasomotor) or in the T. albuginea
vessels surround the follicles
lymphatics run alongside vessels, eventually exiting ovary to drain into lumbar lymph nodes
Primordial follicle
single layer of flattened follicular cells (simple squamous) surrounding a primary oocyte
inactive state
differ from cortical cords by presence of oocyte
Primary follicles
single layer of cuboidal follicular cells
follicle has been activated
zona pellucida begins formation here (may or may not be able to see it)
Secondary follicles
2 or more layers of follicular cells - layer now called stratum granulosa
zona pellucida between oocyte and follicular cells
outer basement membrane - contact outer follicular cells; blood and lymph vessels extend up to (not through) the outer basement membrane
Stromal cells lie outside the center basement membrane, forming theca intern and theca externa
Tertiary follicles
thicker stratum granulosa plus there is a central cavity (follicular antrum)
cluster of stratum granulosa cells left surrounding the primary oocyte (cumulus oophorus); inner layer of these cells = corona radiata - these cells supply the oocyte with nutrients
Ovulation
tertiary follicle wall rupture (due to collagenase release from follicular cells)
primary oocyte release (w/surrounding cumulus)
concurrent antral fluid release facilitates transport of oocyte to uterine tube
completion of meiosis (prior to or after fertilization, depending on species)
completion of fertilization produces a zygote
if unfertilized, oocyte degenerates`
Induced ovulators
need physical stimulation to ovulate
cat, mink, lagomorphs, alpaca, llama
Formation of corpus luteum
rupture of tertiary follicle tears surrounding vessels, resulting in bleeding into the remaining follicular cavity (corpus hemorrhagicum)
stromal cells invade to remove clot
thecal (smaller) cells mix with remaining strantum granulosa (larger) cells, and both cells undergo luteinization and produce progesterone
CL can be yellow in some spp.
Progesterone affect on uterus
stimulate uterine glands (provide nutritional support for zygote/embryo)
inhibit contraction of uterine wall muscles (allowing attachment of embryo)
initial survival of zygote is dependent on progesterone
If fertilization doesn’t occur
if fertilization doesn’t occur - the CL undergoes lysis and is replaced with connective tissue = corpus albicans
uterine endometrium in most species produces prostaglandins needed for luteolysis
p-glandins are passively transported from the uterine vein and lymph directly to the uterine artery (countercurrent exchange) to avoid hormone breakdown
If fertilization occurs
CL persists and remains active for a variable length of time during pregnancy
Can persist throughout entire pregnancy, or placenta can take over
Signs of follicular atresia (degeneration
oocyte and follicular cells: nucleus degenerate (pyknosis, chromatolysis)
basal lamina (esp. zona pellucida): becomes folded and thick
follicular walls collapse in - CT and vessels invade follicle cavity
theca interna cells may become enlarged with cytoplasmic lipid accumulation
Follicular phases
follicles = main feature ==> estrogen
When follicles are main feature, estrogen produced, and animal is priming it for breeding
estrus = high estrogen levels - female will accept male
Luteal phase
CL is main feature ==> progesterone
After ovulation (Release of oocyte), reproductive system will now proceed to prepare for a potential fertilizaed ovum
progesterone produced by the CL sets the stage for implantation and early nourishment
If oocyte is not fertilized the CL will undergo luteolysis
Layers of tubular organs
Tunica serosa (outside) Tunica muscularis (middle) Tunica submucosa (inner middle) Tunica mucosa (innermost)
Tunica mucosa
epithelium, lamina propria (connective tissue below epith) muscularis mucosa (may be absent, if so, then CT blends with tunica submucosa and called tunica mucosa/submucosa)
Uterine tubes: Tunica mucosa/submucosa
Epithelium: simple columnar to pseudostratified columnar, ciliated and secretory (nonciliated) cells
lamina propria/submucosa: loose connective tissue, no glands, ampulla highly folded
Uterine tubes: Tunica muscularis
mainly circular smooth muscle bundles
isthmus = thick muscle layer
Uterine tubes function:
site of fertilization
Three regions of uterine tubes
Infundibulum (proximal, large, funnel shaped, fimbriae)
ampulla - medium wall
Isthmus - distal; narrow and thick walled; joins to uterus; fewer cilia
Uterine tubes - estrus
fimbrial vessel congestion - ciliated epithelial cells beating in a caudal direction + rhythmic muscle contraction results in sweeping motion over ovarian surface, facilitating capture of ovulated oocyte and subsequent movement into lumen of the uterine tube
Later in estrus (diestrus) - oocyte receives nutrients from secretion of tubal epithelial cells
Uterus - functional role
attachment/implantation site of embryo nurture development of embryo/fetus prostaglandin production (CL undergoes luteolysis) assist sperm transport semen comes in here in mare and sow
