Serratus anterior muscle

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Serratus anterior
Serratus anterior
The left side of the thorax.
Latin	musculus serratus anterior
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
Blood:	Lateral thoracic artery (upper part), thoracodorsal artery (lower part)
Nerve:	Long thoracic nerve of Bell (from roots of brachial plexus C5, 6, 7)
Action:	Protract and stabilize scapula, assists in upward rotation.
Antagonist:	Rhomboid major muscle, Rhomboid minor muscle
Dorlands/Elsevier	m_22/12550741

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

Contents 1 Function 2 Innervation 3 Additional images 4 See also 5 External links

[edit] 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 stabilizes the scapula. In addition, it assists in rotating the scapula (glenoid fossa) upward.

[edit] 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). When the muscle loses its innervation, it no longer performs its function of holding the scapula against the rib cage. When a person with such a paralyzed serratus anterior pushes against resistance, the scapula will stick out from the ribs. Because of its resemblance to a wing, this sign is clinically known as a 'winged scapula'.

[edit] Additional images

Surface anatomy of the front of the thorax and abdomen.

[edit] See also

• Serratus posterior inferior muscle
• Serratus posterior superior muscle

[edit] External links

• LUC sera
• GPnotebook 315621454
• 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."

Muscles of the Head — Neck — Trunk — Upper limb — Lower limb— LIST OF ALL MUSCLES

VERTEBRAL COLUMN: trapezius | latissimus dorsi | rhomboid major | rhomboid minor | levator scapulae | (Gray's s121) ANTERIOR AND LATERAL THORACIC WALLS: pectoralis major | pectoralis minor | subclavius | serratus anterior | (Gray's s122) SHOULDER: deltoid | rotator cuff (subscapularis, supraspinatus, infraspinatus, teres minor) | teres major | (Gray's s123) ARM: coracobrachialis | biceps brachii | brachialis | triceps brachii | (Gray's s124) FOREARM: Volar super. | pronator teres | palmaris longus | flexor carpi radialis | flexor carpi ulnaris | flexor digitorum superficialis Volar deep | flexor digitorum profundus | flexor pollicis longus | pronator quadratus Dorsal super. | brachioradialis | extensor digitorum | extensor carpi radialis longus | extensor digiti minimi | extensor carpi radialis brevis | extensor carpi ulnaris | anconeus Dorsal deep | supinator | abductor pollicis longus | extensor pollicis brevis | extensor pollicis longus | extensor indicis | (Gray's s125) HAND: Lateral volar | abductor pollicis brevis | thenar (opponens pollicis, flexor pollicis brevis, adductor pollicis) Medial volar | palmaris brevis | hypothenar (abductor minimi digiti, flexor digiti minimi brevis, opponens digiti minimi) Intermediate | lumbrical | dorsal interossei | palmar interossei | (Gray's s126)