On the other side of the pneumocytes are endothelial cells that line the capillary walls, which is what holds the blood.

而肺泡细一边就是毛细血管壁内皮细，毛细血管携带便是我们亲爱血液。

High blood pressure is a serious problem for the blood vessels because it causes wear and tear on the endothelial cells that line the inside of the blood vessels.

高血压对于血管来说是一种很严重疾病，因为它会导致血管壁内皮细破坏及撕裂。

The thread-like fibers we see — thinner than a human hair — are the remains of those dense, dried out walls of cellulose.

我们到丝状纤维（比人类毛发还要细）是那些紧实干燥纤维素壁（原细壁）残留物。

It starts out as an empty protein packet sent out by the liver to gather up other cholesterols from the blood, and artery walls, and other cells.

它最初是肝脏发出一个空蛋白质包，用来收集血液中其他胆固醇，动脉壁和其他细。

They do build a new, permanent, cellulose wall to separate parent cells from their offspring, though.

过，它们确实建立了一个新、永久纤维素壁，将亲本细与后代细分开。

Now these free-floating platelets don't clump together during regular circulation — that would be terrible — but when the endothelial cells lining a blood vessel wall tear, the underlying collagen fibers are suddenly exposed.

这些自由漂浮血小板在正常血液循环中会凝结在一起——那太可怕了——但是当血管壁内皮细撕裂时，其底层胶原纤维突然暴露出来。

Yeah, the cells, if you think of the walls of the cells, they make the tree strong and there are a couple of chemicals that make up these walls, cellulose and lignin.

是，细，如果你想到细壁，它们使树木强壮， 这些壁由几种化物质构成，包括纤维素和木质素。

So the endothelium is the single layer of cells that line every blood vessel throughout the body.

因此，内皮是遍布全身每条血管壁单层细。

And these are literally bacterial cell walls that are going through the wall of our gut.

而这些实际上是穿透我们肠道壁细菌细壁。