It contains microscopic, fluid-filled tubules that run from the pulp to the underside of the enamel.

它包含微小、充满液体小管，从牙一直到牙釉层。

ADH affects the last two-thirds of these tubes, called the distal convoluted tubule and the collecting ducts.

ADH作用于这些小管终末2/3部分，即远曲小管和集合管。

Beneath that is the medulla, a set of cone-shaped masses of tissue that secrete urine into tiny sac-like tubules.

面是一组锥形组织，将尿液分泌到微小囊状小管中。

If your enamel is worn away, your dentin and its tubules can be exposed.

如你牙釉被磨掉了，你牙本和它小管就会暴露出来。

The targets of the testosterone are the outermost cells in the tubules, called spermatogonia.

睾酮目标是小管中最外层细胞，称为原细胞。

Typically intrarenal AKI's due to damage to the tubules, the glomerulus, or the interstitium —the space between tubules.

通常，肾性AKI是由于肾小管、肾小球或间空间（肾小管间空间）损坏所致。

Now, obviously, if sperm are going to get anything accomplished, they have to leave the seminiferous tubules that made them.

现在，很明显，如想要完成任何事情，它们必须离开制造它们生小管。

And this sperm-making work is supported by cells throughout and around the tubules.

这种制造工作是由遍布小管及其周围细胞支持。

Each one is divided into about 250 sections, called lobules, which are loaded with tightly-coiled seminiferous tubules.

每一个都被分成大约 250 个部分，称为小叶，其中装载着紧密盘绕生小管。

Macula densa cells are located in the distal convoluted tubule and they can sense when levels of sodium and chloride are low.

致密斑位于远曲小管，可以感受到钠和氯水平降低。

And this is showing us the digestive tubules of these animals.

这向我们展示了这些动物消化管。

These tubules are the sperm factories, made of a stratified epithelium surrounding a central fluid-filled lumen.

这些小管是工厂，由围绕充满液体中央管腔分层上皮组成。

As the filtrate leaves the Bowman's capsule it flows into the renal tubule, which is surrounded by the peritubular capillaries.

滤液离开肾小囊后流入肾小管，后者被管周毛细血管网包围。

It's called a cast because it stays in essentially the same cylindrical shape as the tubule.

它被称为管型，是因为它基本上与小管保持相同圆柱形状。

So, let's trace the whole process, starting at the top, with the proximal convoluted tubule or PCT.

所以，让我们追踪整个过程，从顶部开始，用近端卷曲小管或 PCT。

Some substances are removed from blood through the peritubular capillary network into the distal convoluted tubule or collecting duct.

有些物通过管周毛细血管网从血液中移出，进入远曲小管或集合管。

These are basically molds of the insides of your kidney’s tubules, and they can be a sign of kidney disease.

这些基本上是肾小管内部霉菌，它们可能是肾脏疾病征兆。

But the other kind — the type B's — get pushed down the tubule toward the lumen, and turn into primary spermatocytes.

但是另一种，B 型，则是沿着细管进入管腔，然后变成初级母细胞。

But in this case, the sperm develop on the outer edge of the tubule, and progress inward toward the lumen.

但是在这种情况，在小管外缘发育，并向内腔前进。

So when ADH is low, most of the water flows through the the distal convoluted tubule and the collecting duct, giving us diluted urine.

所以当血中ADH水平低时，大部分水就顺着远曲小管和集合管排出体外，尿液也就被稀释。