Suboccipital triangle

Suboccipital triangle
Deep muscles of the back. Triangle is labeled in turquoise.
Gray's	subject #116 402

The suboccipital triangle is a region of the neck bounded by the following three muscles of the suboccipital group of muscles:

• Rectus capitis posterior major - above and medially
• Obliquus capitis superior - above and laterally
• Obliquus capitis inferior - below and laterally

(Rectus capitus 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 occipito-atlantal membrane, and the posterior arch of the 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.

The vertebral artery is accessed here in order to conduct angiography of the circle of Willis.

Contents of the suboccipital triangle

1)Third part of vertebral artery
2)Dorsal ramus of nerve C1-suboccipital nerve
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.

See also

• occipital artery
• greater occipital nerve
• lesser occipital nerve

Additional images

• 

  The vertebral vein.

External links

• SUNY Labs 01:11-0101 - "Muscles of the Back - Suboccipital Triangle"
• Description at myqth.com

This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained within it may be outdated.