Red blood cells (blood) would be your answer! Let me know if I got it wrong
The respiratory system is the breathing system of the body. It works in coordination with the cardiovascular system to make oxygen-rich blood available to the body's organs.
Because it is programmed to go to where it is supposed to go. I believe it is programmed to go to the heart.
It’s actually 24 hours your body needs at least 1 full day of rest for workouts
