Transverse abdominal muscle , t. Transver sa Abdominis , Flat, wide, occupies the deepest position in the anterior lateral part of the abdominal wall.

It starts from the inner surface of cartilages of the lower six ribs (here its muscular teeth are wedged between the teeth of the rib side of the diaphragm), the chest-finding fascia, the inner lip of the iliac crest and from the lateral 2/3 Inguinal ligament. Sheaves follow it horizontally forward and, not reaching the outer edge of the rectus abdominis, pass into the aponeurosis. In this case, above the arcuate line, the aponeurosis lies behind the rectus muscle, and below the line passes to the anterior surface of the rectus muscle. On the median line the bundles of aponeuroses participate in the formation of the white line of the abdomen. From the lower sections of the transverse muscle a small number of bundles are separated, joining to the same bundles from the internal oblique muscle, forming with them a muscle that lifts the testicle.

The site of the transition of the muscle beams of the transverse muscle to the tendon is a convex outward line located in the upper section behind the rectus muscle, and the rest is lateral to its outer edge.

Function: is the abdominal muscle; Flattenes the wall of the abdomen, brings the lower sections of the chest closer.

Innervation: nn. Intercostales (Th7 - Th12), n. Iliohypogastricus, n. Ilioinguinalis,

Blood supply: aa. Intercostales rosteriores, epigastricae superior et inferior, musculophrenica.