The part of the body that never rests is the brain. Even when we are sleeping, the brain is active in performing essential functions such as regulating breathing, heartbeat, and processing information.
The heart is the organ responsible for pumping blood to the rest of the body.
your brain or mind
It gets tired. your body goes to rest.
Your body takes what it needs and then the rest gets exhaled out and goes into the atmosphere.
Any body in the universe is never said to be rest as the electrons inside it keeps moving to and fro and thus no matter on the universe is in standard rest.
It gets the blood from the rest of your body blood that is pumping
his head was to big
A backpack rests on the dorsal part of your body, specifically on the back.
His Big head
It's never good to overload your body...if you are referring to overtraining taking a rest and then going back as making your body ready for more that is not good logic. You can injure yourself amongst other things when you overtrain. Rest periods are very good when you train hard but you should never overtrain your body.
The arteries carry oxygenated blood away from the heart to to the rest of the body.