View source for Decussation of the pyramids

{{Infobox Brain|
  Name            = {{PAGENAME}} |
  Latin           = decussatio pyramidum |
  GraySubject     = 192 |
  GrayPage        = 870 |
  Image           = Gray684.png |
  Caption         = Deep dissection of brain-stem. Lateral view. ("pyramidal tract" visible in red, and "pyramidal decussation" labeled at lower right.)|
  Image2          = |
  Caption2        = |
  IsPartOf        = |
  Components      = |
  Artery          = |
  Vein            = |
  BrainInfoType   = hier |
  BrainInfoNumber = 796 |
  MeshName        = |
  MeshNumber      = |
  DorlandsPre     = d_04 |
  DorlandsSuf     = 12282126  |
}}
{{CMG}}



==Overview==

The two [[Pyramid of medulla oblongata|pyramids]] contain the [[motor fibers]] that pass from the [[brain]] to the [[medulla oblongata]] and [[medulla spinalis]], [[corticobulbar]] and [[corticospinal]] fibers. 

When these pyramidal fibers are traced downward, it is found that some two-thirds or more of them leave the pyramids in successive bundles, and decussate in the [[anterior median fissure of the medulla oblongata]], forming what is termed the '''pyramidal decussation'''. 

Having crossed the middle line, they pass down in the posterior part of the lateral funiculus as the [[lateral cerebrospinal fasciculus]].

==Additional images==
<gallery>
 Image:Gray663.gif|Diagrams of the medulla spinalis.
 Image:Gray679.png|Medulla oblongata and pons. Anterior surface.
 Image:Gray680.png|Decussation of pyramids. Scheme showing passage of various fasciculi from medulla spinalis to medulla oblongata. 
 Image:Gray687.png|Section of the [[medulla oblongata]] through the lower part of the decussation of the pyramids
 Image:Gray688.png|Section of the medulla oblongata at the level of the decussation of the pyramids. 
 Image:Gray689.png|Superficial dissection of brain-stem. Ventral view.
 Image:Gray764.png|The motor tract.
</gallery>

==External links==
* {{eMedicineDictionary|pyramidal+decussation}}
* {{AnatomyAtlasesMicroscopic|17|326}} - "Medula Oblongata"

{{Gray's}}
{{Rhombencephalon}}

[[Category:Anatomy]]

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