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Posterior triangle of the neck | |
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Details | |
Identifiers | |
Latin | Trigonum cervicale posterius Trigonum colli posterius Regio cervicalis posterior |
TA98 | A01.2.02.009 |
TA2 | 239 |
FMA | 57778 |
Anatomical terminology |
The posterior triangle (or lateral cervical region) is a region of the neck.
The posterior triangle has the following boundaries: [1]
Apex: Union of the sternocleidomastoid and the trapezius muscles at the superior nuchal line of the occipital bone
Anteriorly: Posterior border of the sternocleidomastoideus
Posteriorly: Anterior border of the trapezius
Inferiorly: Middle one third of the clavicle
Roof: Investing layer of the deep cervical fascia
Floor: (From superior to inferior)
1) M. semispinalis capitis
2) M. splenius capitis
3) M. levator scapulae
4) M. scalenus posterior
5) M. scalenus medius
The posterior triangle is crossed, about 2.5 cm above the clavicle, by the inferior belly of the omohyoid muscle, which divides the space into two triangles:
A) Nerves and plexuses:
B) Vessels:
C) Lymph nodes:
D) Muscles:
The accessory nerve (CN XI) is particularly vulnerable to damage during lymph node biopsy. Damage results in an inability to shrug the shoulders or raise the arm above the head, particularly due to compromised trapezius muscle innervation.
The external jugular vein's superficial location within the posterior triangle also makes it vulnerable to injury.
The neck is the part of the body on many vertebrates that connects the head with the torso. The neck supports the weight of the head and protects the nerves that carry sensory and motor information from the brain down to the rest of the body. In addition, the neck is highly flexible and allows the head to turn and flex in all directions. The structures of the human neck are anatomically grouped into four compartments: vertebral, visceral and two vascular compartments. Within these compartments, the neck houses the cervical vertebrae and cervical part of the spinal cord, upper parts of the respiratory and digestive tracts, endocrine glands, nerves, arteries and veins. Muscles of the neck are described separately from the compartments. They bound the neck triangles.
Articles related to anatomy include:
In human anatomy, the subclavian arteries are paired major arteries of the upper thorax, below the clavicle. They receive blood from the aortic arch. The left subclavian artery supplies blood to the left arm and the right subclavian artery supplies blood to the right arm, with some branches supplying the head and thorax. On the left side of the body, the subclavian comes directly off the aortic arch, while on the right side it arises from the relatively short brachiocephalic artery when it bifurcates into the subclavian and the right common carotid artery.
The sternocleidomastoid muscle is one of the largest and most superficial cervical muscles. The primary actions of the muscle are rotation of the head to the opposite side and flexion of the neck. The sternocleidomastoid is innervated by the accessory nerve.
The levator scapulae is a slender skeletal muscle situated at the back and side of the neck. It originates from the transverse processes of the four uppermost cervical vertebrae; it inserts onto the upper portion of the medial border of the scapula. It is innervated by the cervical nerves C3-C4, and frequently also by the dorsal scapular nerve. As the Latin name suggests, its main function is to lift the scapula.
The omohyoid muscle is a muscle in the neck. It is one of the infrahyoid muscles. It consists of two bellies separated by an intermediate tendon. Its inferior belly is attached to the scapula; its superior belly is attached to the hyoid bone. Its intermediate tendon is anchored to the clavicle and first rib by a fascial sling. The omohyoid is innervated by the ansa cervicalis of the cervical plexus. It acts to depress the hyoid bone.
The cervical plexus is a nerve plexus of the anterior rami of the first four cervical spinal nerves C1-C4. The cervical plexus provides motor innervation to some muscles of the neck, and the diaphragm; it provides sensory innervation to parts of the head, neck, and chest.
The scalene muscles are a group of three muscles on each side of the neck, identified as the anterior, the middle, and the posterior. They are innervated by the third to the eighth cervical spinal nerves (C3-C8).
The occipital artery is a branch of the external carotid artery that provides arterial supply to the back of the scalp, sternocleidomastoid muscles, and deep muscles of the back and neck.
The transverse cervical artery is an artery in the neck and a branch of the thyrocervical trunk, running at a higher level than the suprascapular artery.
The suprascapular artery is a branch of the thyrocervical trunk on the neck.
The supraclavicular nerve is a cutaneous (sensory) nerve of the cervical plexus that arises from the third and fourth cervical (spinal) nerves. It emerges from beneath the posterior border of the sternocleidomastoid muscle, then split into multiple branches. Together, these innervate the skin over the shoulder.
The carotid triangle is a portion of the anterior triangle of the neck.
The subclavian triangle, the smaller division of the posterior triangle, is bounded, above, by the inferior belly of the omohyoideus; below, by the clavicle; its base is formed by the posterior border of the sternocleidomastoideus.
The occipital triangle, the larger division of the posterior triangle, is bounded, in front, by the Sternocleidomastoideus; behind, by the Trapezius; below, by the Omohyoideus.
Cervical lymph nodes are lymph nodes found in the neck. Of the 800 lymph nodes in the human body, 300 are in the neck. Cervical lymph nodes are subject to a number of different pathological conditions including tumours, infection and inflammation.
The prevertebral fascia is the layer of deep cervical fascia that surrounds the vertebral column. It is the deepest layer of deep cervical fascia.
The inferior deep cervical lymph nodes are one of the two groups of the deep cervical lymph nodes.
The posterior branches of cervical nerves branch from the dorsal rami of the cervical nerves.
The following outline is provided as an overview of and topical guide to human anatomy:
This article incorporates text in the public domain from page 563 of the 20th edition of Gray's Anatomy (1918)