Origin: neuroectoderm: neural crest and neural tube.
Composition:
Central nervous system
lies deep in the body, surrounded and protected by bone. It
consists of the brain, which is incased by the skull,
and the spinal cord, which extends down the canal of the
vertebrate column.
Peripheral nervous system
consists of the three components: ganglia, nerves, and nerve endings or organs of special sense: smell, taste,
sight, hearing, and position of the body in relation to gravity.