The Autonomic Nervous System
The autonomic nervous system supplies nerves to all the internal organs of the body and to the blood vessels. It regulates events which are autonomic. It is controlled by the hypothalamus and its actions are thus not controlled by the brain or will, but are completely reflex and involuntary. As a consequence, we nor the brain knows when the actions will happen.
The autonomic nervous system is divided into two parts:
Fig. 1 The autonomic nervous system
The sympathetic nervous system consists of ganglia - collections of nerve cells - which are situated in front of the vertebral column and travel the length of the body from the thoracic to the lumbar region. These nerve serve a number of purposes:
The parasympathetic nervous system consists of the vagus, oculomotor, facial and glossopharyngeal nerves which branch of to all organs in the chest and abdomen. These nerves serve a number of purposes: