Posterior triangle of the neck
| Posterior triangle of the neck | |
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| Posterior triangle | |
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| 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.
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[edit] Boundaries
It has the following boundaries:
Apex: Union of the sternocleidomastoid and the trapezius muscles at the superior nuchal line of the occipital bone
Anterior: Posterior border of the sternocleidomastoideus
Posterior: Anterior border of the trapezius
Base: Middle one third of the clavicle
[edit] Divisions
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:
- an upper or occipital triangle
- a lower or subclavian triangle (or supraclavicular triangle)
[edit] Contents
A) Nerves and Plexuses:
- Spinal accessory nerve (Cranial Nerve XI)
- Branches of cervical plexus
- Roots and trunks of brachial plexus
- Phrenic nerve (C3,4,5)
B) Vessels:
- Subclavian artery (Third part)
- Transverse cervical artery
- Suprascapular artery
- Terminal part of external jugular vein
C) Lymph Nodes:
- Occipital
- Supraclavicular
D) Muscles:
- Inferior belly of omohyoid muscle
- Anterior Scalene
- Middle Scalene
- Posterior Scalene
- Levator Scapulae Muscle
- Splenius Muscle
[edit] Clinical significance
The Accessory Nerve (CN XI) 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 (e.g., for brushing hair).
The external jugular vein's superficial location also makes it vulnerable to injury.
[edit] Gallery
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Muscles of the neck. Anterior view.
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Posterior triangle of the neck labeled. (Anterior triangles to the left. Occipital triangle labeled at center left.) )
[edit] See also
[edit] External links
- lesson5 at The Anatomy Lesson by Wesley Norman (Georgetown University) (necktriangle)
- lesson6 at The Anatomy Lesson by Wesley Norman (Georgetown University)
- 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 within it may be outdated.
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