Overview
It is enclosed in the rectus sheath, formed by the aponeuroses of the oblique and transverse abdominal muscles. The two recti are separated by the linea alba. Several transverse tendinous intersections cross it.
In the cow, superficial to the ventral abdominal wall and lateral to the midline, the subcutaneous abdominal vein ("milk vein") runs on each side; it drains the udder and passes through the wall at the "milk well".
Origin
Sternum and costal cartilages.
Insertion
Pecten of the pubis, through the prepubic tendon.
Action
Compresses the abdomen and flexes the vertebral column.
Innervation
Ventral branches of the caudal thoracic and cranial lumbar nerves.
Clinical relevance
- Right paramedian abomasopexy, with the cow in dorsal recumbency, fixes the displaced abomasum to the ventral abdominal wall to the right of the midline, through the rectus region. The subcutaneous abdominal vein must be avoided.
- Umbilical hernia in calves occurs through the umbilical ring, in the linea alba between the two recti.