Question

How do your bodys cells get the things they need to survive

Answer 1

The process starts with digestion.  The breaking down of foods into small components.  All the way down till it is converted to ATP.  Is that what you are looking for?

Answer 2

your body gets the things it needs to survive by your brain telling you that its either hungry or thirsty so you can stay energized your body also tells it self when to go to sleep which is something we all need