Eli5: if sleep is meant to repair the brain, how do the parts of the brain that never turn off get repaired?


I really don’t understand how any of it works, but I’ve seen science articles about how your brain basically gets “washed” by spinal fluid while you sleep. My question is basically 2 parts.

1. Why do you have to sleep for this to happen? and 2. If sleep is a requirement, how does your brain clear the parts that are still working while you sleep? Your brain controls all your functions while you sleep and even continues to recognize sounds, ignoring unimportant things but waking you for other things. If sleep is needed for the rest, why not for the parts of your brain doing these functions?

In: 1

Simply put, a big portion of the brain shuts down, and a big part of the cerebral membrane that surrounds the brain and sits beneath the skull contracts.

This causes the brain’s surface to be flooded with cerebral fluids that wash away toxins that build up during the time that we’re conscious.

The fluids wash away these toxins while the internal parts of the brain that deal with consciousness itself deal with the leftover bits of shit from that day with dreams or subconscious examination.

Pretending like the computer is a brain. The OS goes into sleep mode while the user uses canned air to clean out the guts and the BIOS gets updated automatically. Then it comes out of sleep mode.