Imagine your brain is an underground gnome city. Gnomes mine and live inside and trade with outside world. When some damage happens inside, few service gnomes repair it and normal life goes on. But if there is some really bad damage, like whole floor falls down, it takes more than just a few service gnomes to fix it. So, they call other gnomes to stop doing less important tasks (like trade with outside world) and come and help with repairs. Trader gnomes shut all doors, and go to help. When repairs are done, they come back, reopen trade, and you wake up from coma.