The tiny oocyte moves along the fallopian tube.

微小的沿输管运动。

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

但是在出生的时候，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.

初级有46条染色体，但是最终会变成只有23条染色体的配子。

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

每一个泡都由一个生殖组成，也就是，就是未成熟的子。

The truth is, most sperm never reach an oocyte.

事实是，大多数精子永远无法到达。

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

要变成配子就必须要经历第一次减数分裂，而一个人的一生中大概只有400个初级可以做到。

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

这些酶是穿过保护外层的关键。

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巢，巢内存有成千上万的微小袋子，叫做泡，每个泡内都含有一个，即未受精。

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

每一个始基泡中心都有一个未成熟的生殖，叫做初级，被泡包裹。

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，包围初级的滤泡分化为颗粒，使始基泡变为初级泡。

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，初级还停留在第一次减数分裂的前期。

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

排之后，次级会快速地通过腹膜，最后落入输管。

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，它就进入透明带，覆盖质膜的一层糖蛋白。

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

这告诉次级准备完成第二次减数分裂。

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

这两个阶段被排分开，排即：被泡排出，准备好受精。

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

次级泡会在第二次减数分裂中期停止分裂，并且在泡期向黄体期转换的时候等待受精。

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的泡破裂，向输管释放出次级泡。

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，有时候几百万个中只有一打左右通过了所有这些试验最终得到了。

But before that it has to weave through the granulosa cells that form the oocyte's outermost layer, known as the corona radiata.

但在此之前，它必须穿过形成最外层的颗粒，称为辐射日冕。

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.

你会记得在排期，大约一个月一次，巢释放一个次级，该沿着输管流向子宫。