Plan
► Historical aspects of the autonomic nervous system.
► Structural and functional organization of the autonomic nervous system. Comparative characteristics of autonomic and somatic reflexes. Comparative characteristics of sympathetic and parasympathetic divisions of the autonomic nervous systems.
► Structural and functional organization of the metasympathetic (enteric) autonomic nervous system.
► Integration of activities of different parts of the autonomic nervous system to the benefit of an organism.
Historical Aspects of Concept of Autonomic Nervous System
The autonomic nervous system (the ANS) is understood as a complex of central and peripheral nerve structures providing coordinated activity of internal organs for best adaptation of an organism to the variable environment.
First ideas about structure and functions of the ANS date back to the ancient Rome and belong to Galen, Roman physician (129-199 A.D.). It was Galen who introduced the term ?sympathetic? (meaning ?consanguineous?, or providing connection) for the nerve trunk extending along the vertebral column. He described the route and distribution of the vagus (X cranial) nerve in the body. Galen believed that sympathetic nerves were responsible for harmonization of activity of the internal organs.
A more detailed description of sympathetic ganglia was given by Italian anatomist Andreas Vesalius in the 16th century. Vesalius was the first to make a suggestion about sympathetic nerves providing connection between internal organs and the brain.
Further development of the concept of the ANS is connected with the works of French anatomist Francois Bichat (1801) who classified all functions
of the body into animal (somatic) and organic. He believed that the animal (somatic) life was supported by the spinal cord, whereas the organic life was provided by the system of sympathetic nodes (ganglia).