IMPLANTATION OF HUMAN BIRTH AT EARLY DEVELOPMENT STAGES:
Embryo implantation(from lat. im ... - in, in and plantatio - planting, transplanting), nidation of the embryo - implantation of the embryo with the help of villous chorion in the uterine mucosa. Occurs at the blastocyst stage (see Embryonic development) on the 6th – 7th day of post-fertilization or on the 20th – 21st day of the menstrual hemorrhagus. on the posterior wall of the uterus, in half, corresponding to the ovary, from which the superior cell is. By the end of 2 days from the start of implantation, the embryo is completely immersed in the uterine mucosa.
The person I. z. refers to the interstitial type, i.e., the embryo destroys the adjacent area of the mucous membrane with the help of proteolytic. enzymes and completely immersed in its thickness, where it continues to grow. The implant crater formed in this case is closed by the restored mucous above the sunk embryo. The trophoblast plays an important role in this process, to-ry grows vigorously. At the beginning of I. h.the mature blastocyst is adjacent to the uterine epithelium with its embryonic pole coated with cytotrophoblast.
Its surface layer is transformed into a plasmidiotrophoblast, which has pronounced destructive and infiltrating properties. Plasmodium implantation exists only for a short time, and on the 9-10th day of development it degenerates. Cytotrophic cells, flippers, on the contrary, multiply, forming the primary villi. In the process I. h. the uterus mucosa undergoes changes, to-rye can be seen as a reaction to the introduction of the embryo against the background of hormonal influence from the corpus luteum.
It is expressed in the expansion and multiple branching of the spiral arteries and the appearance in their circumference of large, glycogen-rich decidual cells. In the period I. h. anomalies of umbilical cord attachment, forms of the placenta, leading to placental insufficiency may develop.