This article does not cite any references or sources. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (May 2008)

Cauda equina
Cauda equina and filum terminale seen from behind.
File:Human caudal spinal cord anterior view description.JPG
Human caudal spinal cord anterior view
Gray's	subject #208 919
Artery	Iliolumbar artery
MeSH	Cauda+Equina

The cauda equina is a structure within the lower end of the spinal column of most vertebrates, that consists of nerve roots and rootlets from above. The space in which the cerebrospinal fluid is present is actually an extension of the subarachnoid space.

In humans, because the spinal cord stops growing in infancy while the bones of the spine continue growing, the spinal cord in adults ends at about the level of the vertebra L1/L2 , and at birth at L3. However there is some variation in adults and the cord may end anywhere between vertebrae T12 to L3. Individual spinal nerve roots arise from the spinal cord as they do closer to the head, but as the differential growth occurs the top end of the nerve stays attached to the spinal cord and the lower end of the nerve exits the spinal column at its proper level, this results in a "bundle"-like structure of nerve fibres that extends caudally from the end of the spinal cord, gradually declining in number further down as individual pairs leave the spinal column. At the base of the Cauda Equina, there are approximately 10 fiber pairs, 3-5 lumbar, 5 sacral, and the single coccygeal nerve.

Contents 1 Etymology 2 Clinical relevance 3 See also 4 External links

[edit] Etymology

All these roots and rootlets down the vertebral column give the appearance of a horse's tail, which is the meaning of the Latin name cauda equina.

[edit] Clinical relevance

Cauda equina is the part of the spinal cord where a lumbar puncture is performed in order to obtain a sample of cerebrospinal fluid (CSF) for diagnostic purposes. Lumbar puncture, commonly referred to as a "spinal tap", is usually performed at the L3 or L4 intervertebral level, just inferior/distal to the origination of the cauda equina, the conus medullaris.

[edit] See also

• Cauda equina syndrome

[edit] External links

• MedlinePlus Image 19504
• SUNY Labs 02:08-0106
• Cross section at UV pembody/body12a

v • d • e Anatomy of torso (primarily): the spinal cord (TA 14.1.02, GA 9.749) External, dorsal Posterior median sulcus · Posterolateral sulcus Grey matter/ Rexed laminae I-VI: Posterior horn I: Marginal nucleus · II: Substantia gelatinosa of Rolando · III+IV: Nucleus proprius · Spinal lamina V · Spinal lamina VI VII: Lateral horn Intermediolateral nucleus · Posterior thoracic nucleus VIII-IX: Anterior horn Interneuron · Alpha motor neuron (Onuf's nucleus) X: Other Central gelatinous substance · Gray commissure Central canal White matter somatic/ ascending (blue) Posterior/PCML: touch: Gracile · Cuneate Lateral: proprioception: Spinocerebellar (Dorsal, Ventral) · pain/temp: Spinothalamic (Lateral, Anterior) · Posterolateral (Lissauer) · Spinotectal Spinoreticular tract · Spino-olivary tract motor/ descending (red) Lateral: Corticospinal (Lateral) · Ep (Rubrospinal, Olivospinal) Anterior: Corticospinal (Anterior) · Ep (Vestibulospinal, Reticulospinal, Tectospinal) both Anterior white commissure External, ventral Anterior median fissure External, general Cervical enlargement · Lumbar enlargement · Conus medullaris · Filum terminale · Cauda equina

This neuroanatomy article is a stub. You can help Wikipedia by expanding it. v • d • e