What if one of these vessels changes its diameter?

那么如果其中一条血管的直径改变了呢
Let's say it's this one

就说是这条吧
and let's say that it shrinks its diameter so this resistance goes up.

这条血管收缩了所以阻力增加
Goes up here from 5 units to 100 units,

从五个单位变为一百个单位
so I made a big change in that,

这个改变很大
goes up by a factor of 20 so that would be about a factor of two difference in radius,

增大了二十倍可能半径改变了两倍多一点
because of the 4th-power.

因为要根据四次方效应
If this one goes up to 100 now

如果阻力增大到一百
there's more resistance through this particular vessel here

这条血管的阻力变大
and the same resistance through these three,

而这三条血管中的阻力不变
so what happens?

接下来会发生什么
Less flow goes through this vessel

流过这条血管的血液会变少