The transverse abdominis is the innermost of the flat muscles of the abdomen, being placed immediately beneath the internal oblique muscle.
Origin
The transversus abdominis muscle has 4 points of origin running from the inner surface of the 7th to 12th costal cartilages, the thoracolumbar fascia, the iliac crest horizontally, and the inguinal ligament.
Insertion
It has its insertion on the linea alba.
Function
In the respiratory system, the transverse abdominis is an expiratory muscle.
