- Subscapularis muscle
Muscle infobox
Name = Subscapularis muscle
Latin = musculus subscapularis
GraySubject = 123
GrayPage = 440
Caption = Deep muscles of the chest and front of the arm, with the boundaries of the axilla. (Subscapularis visible near center top.)
Origin =subscapular fossa
Insertion =lesser tubercle ofhumerus
Action =rotates medially humerus ; stabilizesshoulder
Blood =transverse cervical artery , cite web |url=http://iris3.med.tufts.edu/headneck/Triangles/Posterior%20Triangle%20of%20the%20Neck.htm |title=Tufts |accessdate=2007-12-11 |format= |work=]subscapular artery
Nerve =upper subscapular nerve ,lower subscapular nerve (C5, C6)
MeshName =
MeshNumber =
DorlandsPre = m_22
DorlandsSuf = 12551017
The Subscapularis is a large triangular muscle which fills thesubscapular fossa .Origin and insertion
It arises from its medial two-thirds and from the lower two-thirds of the groove on the
axillary border (subscapular fossa) of thescapula .Some fibers arise from tendinous laminæ which intersect the muscle and are attached to ridges on the bone; others from an
aponeurosis , which separates the muscle from theTeres major and the long head of theTriceps brachii .The fibers pass lateralward, and, gradually converging, end in a tendon which is inserted into the
lesser tubercle of thehumerus and the front of the capsule of theshoulder-joint .Relations
The tendon of the muscle is separated from the
neck of the scapula by a large bursa, which communicates with the cavity of the shoulder-joint through an aperture in the capsule.Innervation
Innervation to subscapularis is supplied by the upper and lower subscapular nerves, branches of the posterior cord of the
brachial plexus .Actions
The Subscapularis rotates the head of the humerus medially (internal rotation); when the arm is raised, it draws the
humerus forward and downward. It is a powerful defense to the front of theshoulder-joint , preventing displacement of the head of the humerus.
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