Serratus anterior
Serratus anterior
The left side of the thorax.
Gray's	subject #122 438
Origin	fleshy slips from the outer surface of upper 8 or 9 ribs
Insertion	costal aspect of medial margin of the scapula
Artery	lateral thoracic artery (upper part), thoracodorsal artery (lower part)
Nerve	long thoracic nerve (from roots of brachial plexus C5, 6, 7)
Action	protracts and stabilizes scapula, assists in upward rotation.
Antagonist	Rhomboid major, Rhomboid minor, Trapezius

The serratus anterior is a muscle that originates on the surface of the upper eight or nine ribs at the side of the chest and inserts along the entire anterior length of the medial border of the scapula.

Function

The serratus anterior is occasionally called the "boxer's muscle" because it is largely responsible for the protraction of the scapula-that is, the pulling of the scapula forward and around the rib cage that occurs when someone throws a punch. The serratus anterior also helps to stabilize the scapula. In addition, it assists in rotating the scapula (glenoid fossa) upward.

Innervation

The serratus anterior is innervated by the long thoracic nerve, a branch of the brachial plexus. The long thoracic nerve travels inferiorly on the surface of the serratus. The nerve is especially vulnerable during certain types of surgery (for example, during lymph node clearance from the axilla). See winged scapula for more details.

Additional images

Peculiar ribs.	Peculiar ribs.	Left scapula. Costal surface.	The axillary artery and its branches.
Surface anatomy of the front of the thorax and abdomen.

See also

• Serratus posterior inferior muscle
• Serratus posterior superior muscle

External links

• LUC sera
• 315621454 at GPnotebook
• Duke Orthopedics serratus_anterior
• SUNY Figs 04:03-06 - "Superficial muscles of the anterior chest wall."
• SUNY Figs 05:02-07 - "Schematic illustration of a transverse section through the axilla."
• Roche Lexicon - illustrated navigator, at Elsevier 25466.098-1