Tree rings are made of tissue called xylem.

构成年轮的组织被称为木质部。

This capillary motion is in full effect in xylem filaments thinner than human hair.

在木质纤维中毛细作用无处不在，这些木质纤维比人的头发还细。

Right beside the phloem is the tree's other tissue type: the xylem.

在韧皮的旁边是树的另外种组织叫木质。

Through that space stretches the vascular bundle, with xylem to transport water and phloem which transport sugars after photosynthesis.

通过这个空间，延伸出维管束，木质部负责运输，韧皮部负责在光合作用后运输糖。

And there are two main types of cells that make up that vascular tissue: xylem and phloem.

构成维管组织的细胞主要有两种：木质部和韧皮部。

Phloem cells, on the other hand, transport stuff mostly in the opposite direction as xylem cells.

另，韧皮部细胞与木质部细胞的运输向相反。

This evaporation, called transpiration, creates negative pressure in the xylem, pulling watery xylem sap up the tree.

这种蒸发，叫作蒸腾作用，在木质中产生种负压，把液体的木质树液往树上拉。

To accomplish this herculean task, the xylem relies on three forces: transpiration, capillary action, and root pressure.

要完成这样艰巨的任务，木质要依赖于三种力量：蒸腾作用，毛细作用和根压。

There are really tiny tubes called xylem that allow water to move up it.

实际上，存在着称为木质部的微小管道，可以让向上移动。

The xylem, that's the wood inside.

木质部，是里的木材部分。

And the cambium produces phloem and xylem cells.

而形成层则生成韧皮部和木质部细胞。

So these are xylem sap feeders.

所以这些是木质部汁液饲养者。

And xylem is just 95% water.

木质部只有 95% 是。

Carbon and water, more than 1,000 liters of water, in fact, flow freely through the phloem and xylem tubes carry it along.

碳和，实际上超过 1000 升的，自由流动于韧皮部和木质部的管道中。

Sclerenchyma supports organs that are fully mature, and similar to xylem, it has cells that are dead inside (physically, not emotionally) .

厚壁组织支持完全成熟的器官，与木质部相似，它有从内部死亡的细胞（我指的是身体上，而不是情感上）。

And it produces xylem cells inward, right?

它向内生成木质部细胞，对吧？

So the sharpshooter and the cicada, they meet on a tree branch, and they're both chugging their xylem beer.

所以， 尖头虫和蝉在树枝上相遇，它们都在畅饮木质部汁液。

As the plant grows, stem cell clusters called meristems generate new xylem cells, which form bigger pipes to suit the plant's needs.

随着植物的生长，被称为分生组织的干细胞簇产生新的木质部细胞，这些细胞形成更大的管道以适应植物的需要。

Further inside, deeper into the tree, that's the older xylem, and that's the heartwood.

更深处，深入树干内部，那是较老的木质部，也是心材。

After water flows from the roots to the leaves through the xylem, it can exit the plant through the tiny stomata mouths.

通过木质部从根流向叶后，再通过细小的气孔口排出植株。