| 16.31 |
Human birth: day 6-7 implantation |
|
| |
|
|
| |
0.1 - 0.2 mm |
|
| |
5 - 6 days post-ovulation
|
|
| |
|
|
| |
The blastocyst "hatches" from the zona pellucida around the sixth day after fertilization, as the blastocyst enters the uterus. The trophoblast cells secretes an enzyme which erodes the epithelial uterine lining and creates an implantation site for the blastocyst.
|
|
| |
In a cyclical process of hormonal stimulation, the ovary is induced to continue producing progesterone while human chorionic gonadotropin (hCG) is released by the trophoblast cells of the implanting blastocyst. Endometrial glands in the uterus enlarge in response to the blastocyst and the implantation site becomes swollen with new capillaries. Circulation begins,a process needed for the continuation of pregnancy.
|
|
| |
|
|
| |
|
|
| |
|
|
| |
|
|
| |
Copyright © 2009 UCADIA. All rights reserved.
|
|
