AUTONOMIC NERVOUS SYSTEM. The Encephalon contains the autonomic nervous system that controls the involuntary activities, for example, the production of saliva, the beating of the heart and the dilatation of the pupil. It is constituted by the sympathetic system and the parasympathetic system, which govern the involuntary or automatic control. Its main characteristic is to be completely involuntary and unconscious since its function is to control the functioning of our organs, together with the spinal bulb.
