[size=21]The blastocyst usually implants on the posterior uterine wall. The implantation
begins at the end of the first week and is completed by the end of the
second week. During the 6th day, the blastocyst attaches to the
endometrial epithelium. During the second week, the trophoblast
begins to differentiate into the syncytiotrophoblast and the
cytotrophoblast. Penetration of the blastocyst into the mucosa result
from proteolitic enzymes produced by the syncytiotrophoblast. At the
beginning of the second week the blastocyst is embedded in the
endometrial stroma. The endometrial cells around the early conceptus
enlarge and accumulate glycogen and lipids. These cellular changes,
together with the vascular and glandular alterations in the endometrium,
are called the decidual reaction.
Implantation site
1. Endometrium
2. Uterine wall
3. Implanted blastocyst
4. Uterine tube
Blastocyst during implantation
1. Blood vessel
2. Endometrial stroma
3. Syncytiotrophoblast
4. Cytotrophoblast
5. Surface epithelium
6. Epiblast
7. Aminotic cavity
8. Hypoblast
[/size]
begins at the end of the first week and is completed by the end of the
second week. During the 6th day, the blastocyst attaches to the
endometrial epithelium. During the second week, the trophoblast
begins to differentiate into the syncytiotrophoblast and the
cytotrophoblast. Penetration of the blastocyst into the mucosa result
from proteolitic enzymes produced by the syncytiotrophoblast. At the
beginning of the second week the blastocyst is embedded in the
endometrial stroma. The endometrial cells around the early conceptus
enlarge and accumulate glycogen and lipids. These cellular changes,
together with the vascular and glandular alterations in the endometrium,
are called the decidual reaction.
Implantation site
1. Endometrium
2. Uterine wall
3. Implanted blastocyst
4. Uterine tube
Blastocyst during implantation
1. Blood vessel
2. Endometrial stroma
3. Syncytiotrophoblast
4. Cytotrophoblast
5. Surface epithelium
6. Epiblast
7. Aminotic cavity
8. Hypoblast
[/size]
