<Tr> <Td_colspan="2"> Anatomical terminology (edit on Wikidata) </Td> </Tr> <P> The white line (Latin: linea alba) is a fibrous structure that runs down the midline of the abdomen in humans and other vertebrates . In humans linea alba runs from the xiphoid process to the pubic symphysis . The name means white line and the linea alba is indeed white, being composed mostly of collagen connective tissue . </P> <P> It is formed by the fusion of the aponeuroses of the abdominal muscles, and it separates the left and right rectus abdominis muscles . In muscular individuals its presence can be seen on the skin, forming the depression between the left and right halves of a "six pack". </P> <P> Because it consists of mostly connective tissue, and does not contain any primary nerves or blood vessels, a median incision through the linea alba is a common surgical approach . </P>

What abdominal muscle lies to either side of the linea alba