Implantation

怀孕

植入

植入:胚泡植入子宫内膜。
Implantation:
The blastocyst implants itself in the uterine lining.

在胚泡到达子宫以后,它继续发育3-4天,为附着到子宫内膜做好准备。受精约1周后,胚泡的这种附着便开始了,又过约1周后,胚泡已经将自己包埋进富有营养的内膜组织(子宫内膜)。胚泡将自己包埋进子宫内膜的整个过程称为植入(也称着床),借此妊娠便开始了。
植入只有在某些合适的条件下才能够发生。例如,如果受精卵在发育成胚泡之前就到达了子宫,植入是不可能发生的,而且妊娠也就不能构建;如果子宫内膜未为接受胚泡做好准备,结果也是如此。在这两种情况下,受精卵只是死亡和分解。
在一些非常罕见的例子,胚泡不是附着在子宫壁,而是附着在输卵管内壁或子宫之外的一些其他部位(例如腹膜腔)。这种结果叫宫外孕,它不能产生活胎,并且对孕妇有危险。所以,宫外(自希腊语ek: out + topos:位置 = 不在适当的位置)孕必须做手术来终止。

Conception

Implantation

After its arrival in the uterus, the blastocyst continues to develop until, after another three to four days, it is ready to attach itself to the uterine lining. About one week after fertilization this attachment begins, and after about another week the blastocyst has completely buried itself in the nourishing tissues that cover the inner surface of the uterus (the endometrium). The entire extended process of the blastocyst burying itself in the uterine lining is called implantation, and it accomplishes pregnancy.
An implantation can occur only under certain proper conditions. For example, if the zygote should reach the uterus before it has developed into a blastocyst, no implantation is possible and pregnancy cannot be established. The same is true if the uterine lining is not prepared to receive the blastocyst. In both cases, the cell cluster will simply die and disintegrate.
In some very rare instances, the blastocyst will attach itself not to the uterine wall but to the inside of the Fallopian tube or some other place outside the uterus, i.e., in the abdominal cavity. The result is called ectopic pregnancy, which cannot produce a live child and is dangerous to the woman. Therefore, ectopic (Greek ek: out + topos: place = out of place) pregnancies have to be terminated by surgery.

[Course 2] [Description] [How to use it] [Introduction] [Conception] [Historical Notes] [Beginning of Life?] [No definite answer] [Egg and Sperm] [Coitus] [Fertilization] [Segmentation] [Implantation] [Multiple Pregnancies] [Pregnancy] [Birth] [Infertility] [Contraception] [Abortion] [Additional Reading] [Examination]