serratus anterior (costoscapularis, serratus magnus)

Origin

center of lateral aspect of 1st 8-9 ribs

Insertion

• superior & inferior angles & intervening medial border of scapula

Action

• rotates scapula & pulls it forward
• elevates ribs

Innervation

long thoracic nerve from brachial plexus

More general terms

• skeletal muscle (voluntary muscle)