The abdominal wall represents the boundaries of the
abdominal cavity. The abdominal wall is split into the posterior (back), lateral (sides) and anterior (front) walls. There is a common set of layers covering and forming all the walls: the deepest being the extraperitoneal fat, the
parietal peritoneum, and a layer of
fascia which has different names over where it covers (eg transversalis, psoas fascia). Superficial to these, but not present in the posterior wall are the three layers of muscle, the
transversus abdominis (tranvserse abdominal muscle), the
internal (obliquus internus) and the
external oblique (obliquus externus).
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