Term
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Definition
process by which the male and female gametes (spermatozoa and oocyte) fuse
oocyte (plus corona radiate cells ) is ovulated from the ovary and swept into the uterine tube
spermatozoa must undergo Capacitaion and acrosome reaction
fertilization occurs 12-24 hours following ovulation and occurs in the ampulla of the uterine tube |
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Term
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Definition
conditioning in female reproductive tract that allow sperm to pass through the corona cells and undergo acrosome rxn
removal of glycoprotein coat and seminal plasma proteins from sperm overlying acrosome region |
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Term
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Definition
leads to release of enzymes (acrosin- and typsin-like substances) needed to penetrate the zona pellucida
sperm bind to zona pellucida; mediated by ZP3 (enzyme release)--> sperm contacts plasmam membrane) |
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Term
| Following Fertilization: Cortical and Zona Rxns |
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Definition
when the sperm head contacts oocyte surface:
contact leads to release of lysosomal enzymes form crotical granules lining oocyte plasma membrane (Cortical rxn)
oocyte membrane becomes impenetrable to other sperm
zoan pellucida properties are altered to prevent further binding and penetration by other sperm (Zona Rxn) |
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Term
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Definition
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Term
| 8 cell zygote stage (murula) |
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Definition
cell-cell contacts are maximized, segregation of inner and outer (differentiating) cells(become trophoblast)
Inner cells communicate via gap junctions (form the embryo) |
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Term
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Definition
| what will become the placenta |
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Term
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Definition
distinct outer (trophoblast) and inner (embryo) cell mass (localized to one pole)
fluid penetration into intercellular spaces of Icm results in blastocele = blastocyst |
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Term
| Penetration into uterine mucosa |
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Definition
| done by trophoblast cells at embryonic pole of the blastocyst (6 days) |
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Term
| Implantation of blastocyst |
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Definition
| mediated by L-selectins and their receptors, and EMC molecules and thir integrin receptors |
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Term
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Definition
| provuces progesterone, which stimulaates secretory activity of endometriumand is highly vascular |
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Term
| Week two human blstocyst at day 7.5 |
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Definition
partially embedded in the endometrial stroma.
trophoblast inner layer (cytotrophoblast) and an outer syncytiotrophoblast. THe embryoblast is formed by the epiblast and hypoblast and there is also an amniotic cavity developed |
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Term
| Cytotrophoblast and Syncytiotrophoblast |
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Definition
cytotrophoblast - mononucleated cell layer; dive and migrate to syncytiotrophoblast
Syncytiotrophoblast; outer, multinucleated cell layer; produce human chorionic gonadotropin (maintains the corpus colusum causing it to release progesterone) |
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Term
| Human blastocyst at day 9 |
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Definition
deeper embedment; lacunae start to develop in the syncytiotrophoblast
the original entrance defect is closed by a fibrin coagulum |
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Term
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Definition
syncytiotrophoblast erode maternal capillaries
trophoblast lacunae connect to maternal sinusoids
blastocyst start to protrude into uterus lumen
extraembryonic cavity develops outside the exocoelomic cavity |
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Term
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Definition
secondary yolk sac forms within exocoelomic cavity
exocoelomic cyst - portions of "pinched off" exocoelomic cavity
Lacunae are present at both poles
Uteroplacental circulation has begun |
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Term
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Definition
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Term
Abnormal implantation sites
Ectopic pregnancies |
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Definition
occur outside of the uterus; the embryo usually dies in second month of gestation
abdomincal cavity, ampullary region, interstitial implantation, ovarian implantation |
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