Levator scapulae muscle

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.

Anatomy

Attachments

The muscle descends diagonally from its origin to its insertion.

Relations

One of the muscles within the floor of the posterior triangle of the neck, the superior part of levator scapulae is covered by sternocleidomastoid and its inferior part by the trapezius.

It is bounded in front by the scalenus medius and behind by splenius cervicis.

The spinal accessory nerve crosses laterally in the middle part of the muscle and the dorsal scapular nerve may lie deep to or pass through it.

The levator scapulae may lie deep to the sternocleidomastoid at its origin, deep or adjacent to the splenius capitis at its origin and mid-portion, and deep to the trapezius in its lower portion.

Variation

The number of attachments varies; a slip may extend to the occipital or mastoid, to the trapezius, scalene or serratus anterior, or to the first or second rib. The muscle may be subdivided into several distinct parts from origin to insertion. Levator claviculæ from the transverse processes of one or two upper cervical vertebræ to the outer end of the clavicle corresponds to a muscle of lower animals. More or less union with the serratus anterior muscle.

Innervation

The levator scapulae is innervated by 2–3 branches of the 3rd and 4th cervical nerves,

Additional images

File:Levator scapulae muscle animation small2.gif|Position of levator scapulae muscle

File:Gray84.png|A cervical vertebra

File:Gray85.png|Side view of a typical cervical vertebra

File:Gray203.png|Left scapula. Dorsal surface.

File:Gray384.png|Section of the neck at about the level of the sixth cervical vertebra

File:Gray385.png|Muscles of the neck. Lateral view.

File:Gray794.png|Hypoglossal nerve, cervical plexus, and their branches

File:Gray808.png|The right brachial plexus with its short branches, viewed from in front

File:Anterior region of neck.JPG|Levator scapulae muscle

File:Slide1cord.JPG|Brachial plexus. Deep dissection.

File:Slide1ecc.JPG|Brachial plexus. Deep dissection. Anterolateral view

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References

Sources