The nervous system is an organ system containing predominantly neuron and glial cells. In bilaterally symmetrical organism, it is arranged in a network of tree-like structures connected to a central body. The main functions of the nervous system are to regulate and control body functions, and to receive sensory input, process this information, and generate behavior [CUMBO].
Comment:
[homology-note] "Nervous systems evolved in the ancestor of Eumetazoa.[well established][VHOG]" xsd:string {date_retrieved="2012-09-17", external_class="VHOG:0000402", ontology="VHOG", source="ISBN:978-0198566694 Schmidt-Rhaesa A, The evolution of organ systems (2007) p.117", source="http://bgee.unil.ch/"}