And meanwhile, those calcium pumps are working hard to restock the calcium in the sarcoplasmic reticulum.

与此同时，这些钙泵正在努力补充肌浆网中的钙。

Its walls are loaded with calcium pumps — which use ATP to save up a bunch of calcium ions.

它的壁上装有钙泵——它使用三磷酸腺苷来储存一堆钙离子。

That tension means myosin and the calcium pumps are burning up the muscle cells' ATP, and the finite supply of ATP is what makes it impossible to maintain vigorous muscle activity indefinitely.

这种张力意味着肌球蛋白和钙泵正在燃烧肌肉细胞的三磷酸腺苷，而三磷酸腺苷的有限供应使得肌肉活动不可能无限期地保持旺盛。

So calcium flows in through these channels, and to prevent calcium levels from getting too high, cells kick excess calcium right back out with ATP-dependent calcium pumps as well as sodium calcium exchangers.

所以，钙离子通过这些通道流入细胞内，但为防止细胞内的钙离子浓度过高，细胞使用依赖于ATP的钙离子泵、钠钙交换通道将多余的钙离子排出细胞。