The endometrium evolved to make implantation difficult so that only the healthy embryos could survive.

子宫内膜经过演化， 使得着床难以进行因此，只有健康胚胎能够存。

If fertilization doesn't occur, the spiral arteries collapse, and the superficial layers of the endometrium die.

如果卵子没有受精，螺旋动脉将会收缩，子宫内膜也会因此凋亡。

The endometrium evolved to make implantation difficult

子宫内膜不断演化 使得着床变得困难。

The embryo engages in a complex, exquisitely timed hormonal dialogue that transforms the endometrium to allow implantation.

胚胎参与一场复杂而精确计时激素对话，将子宫内膜转变为适合着床状态。

There, it requires another three or so days to implant firmly into the endometrium, the inner lining of the uterus.

在那里， 需要大约三天时间才能牢固地植入子宫内膜，即子宫内膜。

In the uterus, for example, they found one specific fibroblast subtype, S11, that only lived in the inner lining, the endometrium.

例如在子宫中，他们发现了一种特定成纤维细胞亚型S11，这种细胞仅存在于内膜（子宫内膜）中。

The rising estrogen levels in the follicles stimulate the regeneration of the endometrium, building a cushy, well-vascularized habitat for another potential fertilized egg to call home.

卵泡中雌激素水平上升刺激子宫内膜再，为另一个潜在受精卵建立一个舒适、血管发达栖息地。

Estrogen is produced by the ovaries and causes the uterus, lining the endometrium, to thicken again after menstruation so that it is ready to receive an embryo.

雌激素是由卵巢产，它使子宫内膜在月经后再次变厚，以便为胚胎形成做好准备。

And if fertilization didn't happen, the corpus will stop producing progesterone, and the endometrium will start to shed its functional layer. And it starts all over again.

如果没有受精，体将停止产黄体酮，子宫内膜将开始脱落其功能。一切又重新开始了。

During puberty, the monthly menstrual and ovarian cycles begin, which is when the endometrium, or inner lining of the uterus, goes through cyclic changes in response to the ovarian hormones.

在青春期，月经和卵巢周期开始出现，此时子宫内膜（或子宫内衬）对卵巢激素作出反应，发周期性变化。

Because the egg has not been fertilized, the uterus lining called the endometrium is not needed, and hence it breaks down and is lost through the vaginal canal with some blood.

因为卵子没有受精，子宫内膜就不被需要了，因此它会分解，随着一些血液通过阴道管道流失。

If fertilization does happen, then the new embryo snuggles into the endometrium for gestation — but the uterus is only receptive to implantation for a short time, about a week after ovulation.

如果受精确实发了，那么新胚胎会依偎在子宫内膜中怀孕——但是子宫只接受着床很短时间，大约在排卵后一周。

Previous studies have consistently shown associations between adiposity, excess weight, and increased risk of certain cancers, so endometrium, kidney, and gall bladder for women, breast in post-menopausal women, and colon in men.

以前研究一致明肥胖、超重和某些癌症风险增加之间存在关联，因此女性子宫内膜、肾脏和胆囊、绝经后女性乳房和男性结肠。

During the follicular phase of the menstrual cycle, the endometrium thickens in case fertilization occurs, during the luteal phase, spiral arteries emerge to bring more nutrients to support the thick endometrium.

在月经周期中卵泡期，子宫内膜会变厚，有助于受精；黄体期，螺旋动脉产可以为增厚子宫内膜提供更多养分。

And that's the first phase of the uterine, or menstrual cycle — the series of changes that the endometrium goes through every 28 days or so, in response to changing hormone levels, and in coordination with the ovarian cycle.

这是子宫第一阶段，或者说月经周期——子宫内膜每 28 天左右经历一系列变化，这些变化是对激素水平变化响应，并与卵巢周期相协调。