The formation of cold, salty water in the north Atlantic acts like a pump, driving nearly half of Earth's deep ocean water circulatory system.

北大西洋冷盐水的形成就像一个泵，驱动着地球近一半的深海水循环系统。

These pumps drive potassium from the blood into the cells and from there it flows down its concentration gradient into the tubule to be excreted as urine.

这些泵驱使钾从血液进入细胞内，细胞内的钾离子再顺着浓度梯度进入肾小管，以尿液形式排泄。

At the same time, the pumps drive sodium in the opposite direction from the cell into the blood, which allows more sodium to flow from the tubule to the cell down its concentration gradient.

同时，泵以相反方向驱使钠从细胞内进入血液，这使得更多的钠顺着浓度梯度从肾小管流入细胞内。