The tiny oocyte moves along the fallopian tube.

微小的卵母细胞沿输卵管运动。

The truth is, most sperm never reach an oocyte.

事实，大多数精子永远无法到达卵母细胞。

But right around birth, the oocytes stop developing — they get stuck in the first stage of meiosis.

但在出的时候，卵母细胞停止发育——它们卡在减数分裂的第一阶段。

The primary oocyte has 46 chromosomes, but eventually it has to turn into a gamete with only 23 chromosomes.

初级卵母细胞有46条，但最终会变成只有23条的配子。

And, each follicle is made up of a germ cell, also known as an oocyte, which is the immature egg.

每一个卵泡都由一个殖细胞组成，卵母细胞，未成熟的卵子。

This inner machinery includes two ovaries stocked with thousands of tiny sacks called follicles that each contain one oocyte, an unfertilized egg cell.

这套内部机制包含两个卵巢，卵巢内存有成千上万的微小袋子，叫做卵泡，每个卵泡内都含有一个卵母细胞，即未受精卵细胞。

Those enzymes are the key to getting through the oocyte's protective outer layers.

这些酶穿过卵母细胞保护外层的关键。

Meanwhile, the primordial follicle turns into a primary follicle, meaning that the follicular cells that surrounding the primary oocyte develop into granulosa cells.

与此同时，包围初级卵母细胞的滤泡细胞分化为颗粒细胞，使始基卵泡变为初级卵泡。

Each primordial follicle has a single immature sex cell called the primary oocyte at the core, and a layer of follicular cells surrounds this.

每一个始基卵泡中心都有一个未成熟的殖细胞，叫做初级卵母细胞，被卵泡细胞包裹。

This tells the secondary oocyte to get ready to complete its second meiotic division.

这告诉次级卵母细胞准备完成第二次减数分裂。

To do this, the primary oocytes have to complete meiosis 1, and in a person's lifetime only about 400 successfully do that.

要变成配子必须要经历第一次减数分裂，而一个人的一中大概只有400个初级卵母细胞可以做到。

That's when the nearly 2 centimeter sized follicle ruptures and releases the tiny secondary oocyte into the fallopian tube.

此时将近2cm的卵泡破裂，向输卵管释放出次级卵泡。

These two phases are separated by ovulation, which is when the follicle ruptures and releases an oocyte that is ready to be fertilized.

这两个阶段被排卵分开，排卵即：卵母细胞被卵泡排出，准备好受精。

In fact, sometimes only a dozen or so of the original millions make it through all those trials to actually reach an oocyte.

事实上，有时候几百万个卵母细胞中只有一打左右通过了所有这些试验最终得到了卵母细胞。

After ovulation, the secondary oocyte makes a very quick journey through the peritoneal space and lands in the fallopian tube.

排卵之后，次级卵母细胞会快速地通过腹膜，最后落入输卵管。

The first stage lasts from infancy to puberty, and during this stage the primary oocyte remains stuck in the prophase step of meiosis 1.

第一阶段从婴儿期到青春期，初级卵母细胞还停留在第一次减数分裂的前期。

Once it's past that, it runs into the zona pellucida, a layer of glycoprotein that covers the oocyte's plasma membrane.

一旦过了这个阶段，它进入透明带，覆盖卵母细胞质膜的一层糖蛋白。

You'll remember that during ovulation, about once a month, an ovary releases a secondary oocyte that heads down the fallopian tube and toward the uterus.

你会记得在排卵期，大约一个月一次，卵巢释放一个次级卵母细胞，该卵母细胞沿着输卵管流向子宫。

The secondary oocyte stops in metaphase of meiosis 2, and waits for fertilization as the menstrual cycle transitions into the luteal phase.

次级卵泡会在第二次减数分裂中期停止分裂，并且在卵泡期向黄期转换的时候等待受精。

They also prepare the uterus to receive the oocyte, which is now on its way down a fallopian tube, where it might meet a nice young sperm.

它们还准备子宫接收卵母细胞，卵母细胞现在正在输卵管中，在那里它可能会遇到一个好的年轻精子。