Central nervous system

Central nervous system
Schematic diagram showing the central nervous system in yellow, peripheral in orange
Details
Lymph	224
Identifiers
Latin	systema nervosum centrale pars centralis systematis nervosi[1]
Acronym(s)	CNS
MeSH	D002490
TA98	A14.1.00.001
TA2	5364
FMA	55675
Anatomical terminology [edit on Wikidata]

The central nervous system (CNS) is the part of the nervous system consisting of the brain and spinal cord, the retina and optic nerve, and the olfactory nerve and epithelia. The CNS is so named because the brain integrates the received information and coordinates and influences the activity of all parts of the bodies of bilaterally symmetric and triploblastic animals—that is, all multicellular animals except sponges and diploblasts. It is a structure composed of nervous tissue positioned along the rostral (nose end) to caudal (tail end) axis of the body and may have an enlarged section at the rostral end which is a brain. Only arthropods, cephalopods and vertebrates have a true brain, though precursor structures exist in onychophorans, gastropods and lancelets.

The rest of this article exclusively discusses the vertebrate central nervous system, which is radically distinct from all other animals.