how our brains know to use our organs to keep us alive.


Like, how do they know they need lungs for oxygen? How do they know to send waste to our kidneys? How do they know to always keep the heart beating?

In: Biology

They don’t “know” they are just doing what they are preprogramed to do, if they didn’t you would die and that would mean that evolution would remove you from the group of functioning humans.

Evolution. The brain is “prepackaged” to do certain things. That’s why every brain follows a similar “map” within species and down a family line. E.g., all mammal brains share certain structures. All human brains (except disease and mutation) have a really big frontal lobe (relative to the rest of the brain).

The process of getting to such a complex brain took literally millions of years through the evolution of life and millions of now extinct species along the way. it seems really abrupt to spring into life as an individual at the end of that very long chain of change, but we are actually just a gradual step along a meandering path.

You know how we’re taught that we have 5 senses? That’s wrong and wrong by a lot. We have possibly 20ish senses. Many of them are how the brain “knows” what to do.

For instance, you have a sense which, well, senses CO2 levels in the blood (you don’t have a sense for oxygen). When this sense picks up that the CO2 level in your blood is too high different parts of the brain are activated which tell the involuntary muscles in you respiratory system to increase which purges the blood of the excess CO2.

The brain doesn’t control a lot, maybe most, of the organs. The heart beats on its own even without a brain. The liver filters blood on its own, even without a brain. Your stomach digests food on its own, even without a brain. And so on and so on. Each organ is a fine tuned machine that does “one job” and it doesn’t know or care about the other organs. All it knows is it takes an input and produces an output.