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.

就在韧皮的旁边是树的另外种组织叫木质。

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，在木质中种负压，把液体的木质树液往树方拉。

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

通过这个，伸出维管束，木质部负责运输水，韧皮部负责在光合作用后运输糖。

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% 是水。

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.

另方面，韧皮部细胞与木质部细胞的运输方向相反。

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。

And if we zoom in, we'll notice its xylem and phloem cells snuggled together, just like they were in the stem.

如果我们放大，我们会注意到它的木质部和韧皮部细胞依偎在起，就像它们在茎中样。

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

韧皮部旁边是树的另种组织类型：木质部。

And pro-tip, xylem is one of my favorite scrabble words.

专业提示，木质部是我最喜欢的拼字游戏之。

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，而不是情感）。

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

碳和水，实际超过 1000 升的水，自由流动于韧皮部和木质部的管道中。

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

随着植物的长，被称为分组织的干细胞簇新的木质部细胞，这些细胞形成更大的管道以适应植物的需要。

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

水通过木质部从根流向叶后，再通过细小的气孔口排出植株。

This process, called osmotic movement, creates nutrient-rich xylem sap, which will then travel up the trunk to spread those nutrients through the tree.

这个过程，叫做渗透运动，会营养丰富的木质树液，这些树液会沿着树干向把营养传送到整棵树。

That causes air bubbles to form in the xylem, a specialised tissue that transports water from a plant's roots to its leaves.

这会导致木质部中形成气泡，木质部是种将水从植物根部输送到叶子的特殊组织。

And where these two forces pull the sap, the osmotic movement at the tree's base creates root pressure, pushing fresh xylem sap up the trunk.

这两种力量推动树液向，树根部的渗透作用也树压，把新鲜的木质树液推树干。