S sod and mat said earlier that calcium sits pretomly outside, but you got some calcium inside of muscle. If you have a look at the heart forex, it's throwing three sodium out, two potassium in. You've got leaky potassium channels making it even more positive outside compared to inside. So that's the important of the soting potassium pump for neurons. And that calcium last part at the end of the nuron is what tells the neuro transmitter, whatever that is, to then release to go into the next cell to tell it to do something.