This chapter deals with the autonomic nervous system (ANS). This regulates the operation of the internal organs and supports the activity of the body as a whole. The autonomic nervous system is not a separate nervous system but is the efferent pathway that links those areas within the brain concerned with the regulation of the internal environment to specific effectors such as blood vessels, the heart, and the gut. The chapter points out that the ANS does not pass directly to the effector organs, but rather they synapse in autonomic ganglia, which are located outside the CNS. The chapter looks at fibres. These project from the CNS to the autonomic ganglia. The latter are called preganglionic fibres, and those that connect the ganglia to their target organs are called postganglionic fibres. The sensory nerves of the internal organs are known as visceral afferents.
