Implantation Flashcards
1
Q
what is implantation
A
- process of embryo attaching to endometrium of uterus
- then invades epithelium (layer of endometrium closest to lumen)
- establishes connections to maternal circulation to form placenta
2
Q
list three stages of implantation
A
- apposition
- adhesion
- invasion
3
Q
describe apposition of implantation
A
- blastocyst contacts implantation site of endometrium
4
Q
describes adhesion of implantation
A
- trophoblast cells of blastocyst attach to receptive endometrial epithelium
5
Q
describe invasion of implantation
A
- invasive trophoblast cells (syncitiotrophoblast cells) cross endometrial epithelial basement membrane (via digestive enzymes) & invade endometrial stroma
6
Q
around what day does implantation occur & what event precedes it
A
~7 days after conception
- after blastocyst hatches from zona pellucida
7
Q
in what stage must maternal endometrium be in for embryo to attach
A
when maternal endometrium is in receptive phase
8
Q
_______ & _________ are important regulators of endometrial receptivity
A
- oestrogen
- progesterone
9
Q
how often does receptive phase occur & how long does it last & when does it occur specifically
A
- occurs during each cycle
- lasts for only a few days
- in normal 28-day menstrual cycle, occurs on days 16-22 which is 5-10 days after LH surge
