Normal implantation zone
In order that implantation can take its normal course, the blastocysts and the uterine mucosa must be able to interact. These two, independent structures must, therefore, undergo synchronous changes. The implantation normally takes place in the superior and posterior walls of the uterine body (corpus uteri) in the functional layer of the endometrium during the secretory phase of the cycle.

- Uterine cavity
- Isthmus of the tube
- Uterine tube (tuba uterina)
- Uterine cervix (cervix uteri)
Fig. 14
Normal implantation zone of the blastocyst in the superior and posterior wall of the uterine cavity.