Question

Heart starts beating fast when you are scared but who tells heart that you are scared? Who tells the lungs that your body needs more oxygen which increases the breathing rate?

Answer 1

The human brain can sense emotions. It can distinguish whether the person is happy, sad or scared. It then controls the thought processes and tells the body to act according to that perticular emotions. That is why our heart starts beating faster when our brain sense any kind of threat situation that can harm the body.