Implantation Flashcards
Implantation refers specifically to the attachment of the fertilized egg to the uterine lining, which occurs ______.
approximately 6 or 7 days after conception
Implantation refers specifically to ______, which occurs approximately 6 or 7 days after conception.
the attachment of the fertilized egg to the uterine lining
Implantation requires a direct and coordinated interaction between the blastocyst, specifically the outer _____, and the hormonally primed lining of the uterine cavity.
trophectoderm
What is blastocyst hatching? When does it occur?
is the process when the blastocyst “escapes” from the zona pellucida
around day 6-7 after ovulation
______ is the process where by the endometrial stromal cells, fibroblasts, are transformed into round decidual cells.
Decidualization
This is the process when the blastocyst “escapes” from the zona pellucida around day 6-7 after ovulation.
blastocyst hatching
What is decidualization?
the process where by the endometrial stromal cells, fibroblasts, are transformed into round decidual cells
Decidualization is dependent upon ____ and ____.
progesterone
cAMP
The ______ layer resides under the implanting embryo.
decidua basalis
The _____ layer overlies the embryo.
decidua capsularis
The _______ layer covers the remainder of the uterine surface.
decidua parietalis
There is only a finite period of time that the epithelium lining of the uterus is prepared to accept the implantation of the blastocyst. This occurs at day _____ of the menstrual cycle.
20-24
The _______ of the blastocyst produces human chorionic gonadotropin (hCG), which maintains the corpus luteum and therefore the progesterone.
trophoectoderm
The trophectoderm of the blastocyst produces ______, which maintains the corpus luteum and therefore the progesterone.
human chorionic gonadotropin (hCG)
hCG is closely related to what other hormone?
luteinizing hormone (LH)
hCG also has _____ and ______ properties and likely is critical for implantation.
immunosuppressive
growth-promoting
Other immunosuppressive factors produced by the pre-implantation embryo are ______ and ______.
early pregnancy factor (EPF)
platelet-activating factor (PAF)
The first stage of implantation is _____.
Apposition
What is apposition?
the first stage of implantation; a loose unstable connection between the trophectoderm and the endometrial lining
What is the 2nd stage of implantation?
adhesion
What is adhesion?
the 2nd stage of implantation; a stronger connection created by ligand-receptor interactions via integrins and heparins
What 2 ligand-receptor molecules are important for adhesion in implantation?
integrins
heparins
What side of the blastocyst embeds first?
the inner cell mass side
What is the 3rd phase of implantation?
invasion
What is invasion?
when the trophoblastic cells rapidly proliferate and
differentiate into syncytiotrophoblasts and cytotrophoblasts
The ______ extend long protrusions and secrete tumor necrosis factor-α (TNF-α), which interferes
with the expression of cadherins and ß-catenin, thereby assisting with the dislodgement of the epithelial cells.
syncytiotrophoblasts
The syncytiotrophoblasts extend long protrusions and secrete _____, which interferes with the expression of cadherins and ß-catenin, thereby assisting with the dislodgement of the epithelial cells.
tumor necrosis factor-α (TNF-α),
The syncytiotrophoblasts extend long protrusions and secrete tumor necrosis factor-α (TNF-α), which interferes
with the expression of ______, thereby assisting with the dislodgement of the epithelial cells.
cadherins and ß-catenin
Implantation most frequently occurs in the _____ of the uterus.
upper posterior wall in the midsagittal plane
If implantation occurs near the cervix then a _____ can occur.
placenta previa
If the implantation site occurs over the site of a prior uterine scar then ______ may develop.
placenta accreta
