Posterior triangle of the neck
|Posterior triangle of the neck|
|The triangles of the neck. (Posterior triangles to the right. Sternocleidomastoideus runs vertically. Occipital triangle labeled at right, and subclavian triangle labeled at bottom.)|
|Side of neck, showing chief surface markings. (Nerves are yellow, arteries are red.)|
|Latin||regio cervicalis lateralis, trigonum cervicale posterius|
|Gray's||subject #145 563|
The posterior triangle (or lateral cervical region) is a region of the neck.
It has the following boundaries:
- in front, by the Sternocleidomastoideus
- behind, by the anterior margin of the Trapezius
- its base is formed by the middle third of the clavicle
- its apex, by the occipital bone
Occipital and subclavian triangles
The posterior triangle is crossed, about 2.5 cm above the clavicle, by the inferior belly of the Omohyoideus, which divides the space into two triangles:
It contains the accessory nerve, which crosses the triangle from the upper 1/3 of sternocleidomastoideus to the lower 2/3 of the trapezius.
It is particularly vulnerable to damage at lymph node biopsy, where damage results in an inability to shrug the shoulders or raise the arm above the head (eg, for brushing hair)
- Norman/Georgetown lesson6
- SUNY Figs 24:01-02 - "Identification of the muscles associated with the posterolateral triangle."
- lateral+cervical+region at eMedicine Dictionary
This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained herein may be outdated. Please edit the article if this is the case, and feel free to remove this notice when it is no longer relevant.