1) Define Automatic, central, peripheral nervous system. 2) Define Brain 3) Describe Red blood cell with its symptoms, preventive measure, and disease caused by it.
A brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It is located in the head, usually close to the sensory organs for senses such as vision. It is the most complex organ in a vertebrate's body.
