Rectus abdominis

The rectus abdominis, often referred to as the abs, are a pair of muscles with their origins at the pubis (pubic symphysis, pubic tubercle and crest) that extend vertically to insert on the xiphoid process of sternum and costal cartilages of the 5th to 7th ribs

Typically each muscle is divided by 3 or 4 tendinous intersections

Image illustrating the rectus abdominis