Turns out to have a lot of relevance in the cardiovascular system,

事实证明它和心血管系统运作息息相关
but has relevance everywhere.

但也能适用于其他地方
It has relevance in terms of getting water to all the faucets in this building.

甚至和给这栋楼里的每个水龙头供水也沾边
You have to solve the same problem,

这些所需要解决的问题是相同的
and that is generating enough pressure

就是产生足够的压力
to allow fluid to move through a length of tubing.

使液体能够流过全部管道
We'll think about a typical length of tubing

我们想像一根典型长度的管路
and we'll make it as simple as possible.

同时把问题尽可能地简化
It's a vessel that has a constant diameter or radius

对这段血管其直径或者半径恒定
and a known length.

长度已知
Fluid is going to flow in one end of this vessel

液体将从血管的一端流入
and it's going to flow out the other,

从另一端流出