View source for Suboccipital triangle

{{Infobox anatomy
| Name        = Suboccipital triangle
| Latin       =
| Image       = Suboccipital triangle dissection - Suboccipital triangle.png
| Caption     = Artist depiction of the muscles that border the suboccipital triangle.
| Image2      = Suboccipital triangle11.png
| Caption2    = Muscles that border the suboccipital triangle. {{legend|#3366FF|[[Rectus capitis posterior major muscle]]}}{{legend|#00FF00|[[Obliquus capitis superior muscle]]}}{{legend|#FF0000|[[Obliquus capitis inferior muscle]]}}
| System      =
| Precursor   =
}}
The '''suboccipital triangle''' is a region of the [[neck]] bounded by the following three muscles of the [[suboccipital muscles|suboccipital group of muscles]]:
* [[Rectus capitis posterior major]] - above and medially
* [[Obliquus capitis superior]] - above and laterally
* [[Obliquus capitis inferior]] - below and laterally
(Rectus capitis posterior minor is also in this region but does not form part of the triangle)

It is covered by a layer of dense fibro-fatty tissue, situated beneath the [[semispinalis capitis]].

The floor is formed by the [[posterior atlantoöccipital membrane|posterior atlantooccipital membrane]], and the [[posterior arch]] of the [[Atlas (anatomy)|atlas]].

In the deep groove on the upper surface of the posterior arch of the atlas are the [[vertebral artery]] and the first cervical or [[suboccipital nerve]].

In the past, the vertebral artery was accessed here in order to conduct [[angiography]] of the [[circle of Willis]]. Presently, formal angiography of the circle of Willis is performed via catheter angiography, with access usually being acquired at the common femoral artery. Alternatively, a computed tomographic angiogram or magnetic resonance angiogram is performed.

==Contents of the suboccipital triangle==

1) Third part of [[vertebral artery]]<br />
2) Dorsal ramus of nerve C1-[[suboccipital nerve]]<br />
3) [[Suboccipital venous plexus]]

The purpose of these muscles is to provide fine motor function in movements of the head. The actions of [[trapezius]], [[sternocleidomastoid]] and other larger muscles that move the head are refined by the relatively small suboccipital triangle muscles.

==Additional images==
<gallery>
 File:Suboccipital triangle - animation01.gif|Muscles that border the suboccipital triangle. Animation.
 File:Suboccipital triangle - animation03.gif|Close up.
 File:Suboccipital triangle.PNG|Deep muscles of the back. Triangle is labeled in turquoise.
 File:Gray563.png|The vertebral vein. 
</gallery>

==See also==
* [[Suboccipital muscles]]
* [[Occipital artery]]
* [[Greater occipital nerve]]
* [[Lesser occipital nerve]]

==References==
{{Gray's}}

==External links==
{{Commonscat|Suboccipital triangle}}
* {{SUNYAnatomyLabs|01|11|01|01}} - "Muscles of the Back - Suboccipital Triangle"
* [http://wnor.myqth.com/deepback.html Description at myqth.com]

{{Superficial anatomy}}

[[Category:Human head and neck]]
[[Category:Triangles of the neck]]

{{Portal bar|Anatomy}}