The transversalis fascia (TF) covers the deep surface of the transverse abdominis muscle (TAM), the quadratus lumborum muscle QLM) and the psoas major muscle (PMM). Anteriorly it covers the deep surface of the rectus abdominis muscle. It is covered by the peritoneum.
The layers of the abdominal wall from the outside are: external oblique muscle (EOM), internal oblique muscle (IOM) and TAM.
The latissimus dorsi muscle (LDM) and the erector spinae muscle (ESM) are superficial to the QL muscle.
TF = green line + red arrow; peritoneum = brown line + brown arrow; blue arrows = anterior aponeuroses of abdominal muscles; yellow arrow = posterior aponeurosis of TAM; green arrow = TAM; magenta arrow = IOM; black arrow = EOM; red asterix = QLM; magenta asterix = LDM; blue asterix = ESM; yellow asterix = PMM.
