[eli5] Why can’t we control our body, other than using specific muscles?

Question

Why I(me, awareness) can’t send signals to my body to create or destroy an organ, but can use muscles? (Both are electric signals)

In: Biology

Answer 1

….well we can.

I mean with enough practice people are able to learn to control innvoluntary muscles, like heart – however it just takes far too much time to be a sensible thing to do for most folks.