So that your muscles work?
the circulatory system carries all the oxygen you breathe in and give it to the muscular system. that way, it can function correctly adn keep your body healthy. also, without muscles, the heart wouldn't function since it is a cardiac muscle.
Hydration
i guess not.
Basically eating healthy, going to the washroom regularly, exercising daily and sleeping 6-9 hours each night are all you need to keep your system healthy.
to remain healthy u must keep the muscular strength and endurance, flexibility, body composition, and cardeovascular/respitory.
The muscular system is need because it supports the body and allows for movement
To move and to drive.
Humans need to keep healthy if they are to avoid the risk of dying prematurely.
Crayfish have muscles. They need them to move.
you need to not eat junk food to keep your heart healthy
they need them to keep healthy?
We need vitamins to keep our body strong and healthy.