Neurophysics (or neural physics) is the branch of medical physics dealing with the nervous system including the brain and the spinal cord and the nerves. The nervous system is the part of an animal's body that coordinates its voluntary and involuntary actions and transmits signals to and from different parts of its body. Nervous tissue first arose in wormlike organisms about 550 to 600 million years ago. In vertebrate species it consists of two main parts, the central nervous system (CNS) and the peripheral nervous system (PNS).
