Organs respond to the external stimulus by a fraction of second

Organs respond to the external stimulus by a fraction of second. How do you feel about such controlling mechanism of Human body ?
A. 1) Organs respond to the external stimulus by a fraction of second. It is due to reflex action.
2) These are very important, as they save us from painful or dangerous stimuli.
3) Reflex actions are very fast, immediate, automatic and involuntary responses of
the body. '
4) Reflexes occur without thinking,
5) Brain is not involved in the several reflexes.
Ex: Withdrawing our hand wheh We touch hot object