The right answer is C) an organ
* The central nerve system is an organ system composed of two organs: the encephalon and the spinal cord.
* An organ is a space defined by a serosa, where cells from distinct embryological lineages collaborate in tasks that none of them would accomplish alone.
* The spinal marrow (according to the new nomenclature), or spinal cord (in the old nomenclature), refers to the part of the central nervous system that extends below the brainstem at the level of the medulla oblongata. It is contained in the spinal canal (channel formed by the juxtaposition of the foramens of the vertebrae), which supports and protects it.
It consists of neurons and glial cells. Its main function is the transmission of nerve messages between the brain and the rest of the body. It also contains independent neural circuits that control a number of reflexes.
