Subclavius muscle

The subclavius is a small triangular muscle, placed between the clavicle and the first rib.[1] Along with the pectoralis major and pectoralis minor muscles, the subclavius muscle makes up the Anterior Axioappendicular Muscles also known as anterior wall of the axilla.[2]

Subclavius muscle
Subclavius muscle (shown in red).
Deep muscles of the chest and front of the arm, with the boundaries of the axilla. (Subclavius visible at upper left, above first rib.)
Details
Originfirst rib and cartilage
Insertionsubclavian groove of clavicle (inferior surface of middle one third of the clavicle)
Arterythoracoacromial trunk, clavicular branch
Nervesubclavian nerve
Actionsdepression of clavicle
elevation of first rib
Identifiers
Latinmusculus subclavius
TAA04.4.01.007
FMA13410
Anatomical terms of muscle

Structure

It arises by a short, thick tendon from the first rib and its cartilage at their junction, in front of the costoclavicular ligament.[1]

The fleshy fibers proceed obliquely superolaterally, to be inserted into the groove on the under surface of the clavicle.

Innervation

The nerve to subclavius (or subclavian nerve) innervates the muscle. This arises from the junction of the fifth and sixth cervical nerves, from the Superior/upper trunk of the brachial plexus.

Variation

Insertion into coracoid process instead of clavicle or into both clavicle and coracoid process. Sternoscapular fasciculus to the upper border of scapula. Sternoclavicularis[3] from manubrium to clavicle between pectoralis major and coracoclavicular fascia.[1]

Function

The subclavius depresses the shoulder, carrying it downward and forward. It draws the clavicle inferiorly as well as anteriorly.

The subclavius protects the underlying brachial plexus and subclavian vessels from a broken clavicle - the most frequently broken long bone.

Additional images

References

This article incorporates text in the public domain from page 438 of the 20th edition of Gray's Anatomy (1918)

This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.