Rectus Abdominis
Abdomen & Core
The 'six-pack' muscle — technically it's all one muscle with tendinous inscriptions creating the segments.
Function
Flexes trunk, compresses abdomen
Origin
Pubic symphysis and pubic crest
Insertion
Xiphoid process and costal cartilages 5-7
Innervation
Intercostal nerves T7-T12