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[[de:R�ckenmark]] [[es:sinapsis]]

The spinal cord is the extension of the [[central nervous system]] that is enclosed in and protected by the [[spine (anatomy)|vertebral column]]. It consists of [[neuron|nerve cells]] and their connections ([[axon]]s and [[dendrite]]s), with both [[gray matter]] and [[white matter]], the former surrounded by the latter.

The vertebral column consists of 5 segments. From top to bottom those are: the [[cervical]] verterbrae, the thoracic, the lumbar, the [[sacrum]] and the [[coccyx]].


==[[Embryology]] of the human spinal cord==
In the [[fetus]], the spinal cord extends all the way down to the [[sacral vertebrae]]. As the person matures, the spinal cord shortens relative to the rest of the body, so at adulthood, the spinal cord only reaches up to around the level of L1 (the first [[lumbar vertebrae]]) where it terminates and the [[cauda equina]] begin - this is why [[lumbar puncture]]s are usually carried out in the adult at the level of L3/L4.


==[[Anatomy]] of the human spinal cord==
It originates in the inferior end of the [[medulla oblongata]], exiting the [[skull]] via the [[foramen magnum]]. It is wrapped in three layers of membranes, called [[meninges]].

The spinal cord carries [[sensory signals]] and [[motor innervation]] to most of the [[skeletal muscle]]s in the body. Just about every [[voluntary muscle]] in the body below the head depends on the spinal cord for control.
Similarly, most [[cutaneous sensation]] below the neck is transmitted via the spinal cord.
Most of the [[sympathetic pathway]]s and the lower (i.e. non-[[vagus nerve|vagal]]) [[parasympathetic pathway]]s also go through the spinal cord.

==[[Disease]]s of the spinal cord==
Damage to the spinal cord, also known as [[myelopathy]] can result in [[paraplegia]] or [[quadriplegia]], depending on the level of the spinal cord that the damage was done.

====References====
* Adapted from the [[Wikipedia]] article, "Spinal cord" http://www.wikipedia.org/wiki/Spinal_cord August 7, 2003