For example, we can will ourselves breathe/blink faster, or choose to hold our breath. But at the same time, we can’t will a faster or slower heart rate or digestion when it might be advantageous to do so. What is the difference in the muscles involved or brain regions associated with these automated functions?
In: Biology
Basically, because of evolution.
Some body functions (like breathing) can be left automated most of the time, but have a few instances where it’s more useful to control them (for example, when you’re running for a long time and need to breath manually to be more efficient).
Other body functions, like your heart rate, or the various hormones that automatically regulate your body are best left doing their own things. Either their work is passive and controlling them would be useless (like your heart or your digestion), or their purpose is to regulate your body and send you warning signals when needed (that’s what hormones do). Controlling those things would result in more bad than good, so we can’t.
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