6.1. Overview of the Nervous Systems of the Body

Organisation of the Nervous System

The nervous system can be classified by its structures or functions.

Structurally, the nervous system is divided into the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS consists of the brain, spinal cord and retina, while the PNS is, basically, everything else.

Functionally, the nervous system is made up of the somatic nervous system (SNS) and the autonomic nervous system (ANS), and each of these divisions contains further subdivisions (see the accompanying diagram).

The following sections will examine the nervous system by its functional classification.