The " posterior surface " is concave, and directed backward and downward; that of the first gives attachment to the sternothyroideus, those of the third to the sixth inclusive to the transversus thoracis muscle, and the six or seven inferior ones to the transversus abdominis muscle and the diaphragm.
22.
In medical vernacular, the abdominal wall most commonly refers to the layers composing the anterior abdominal wall which, in addition to the layers mentioned above, includes the three layers of muscle : the transversus abdominis ( transverse abdominal muscle ), the internal ( obliquus internus ) and the external oblique ( obliquus externus ).
23.
It is retained in contact with the posterior wall of the abdomen by the peritoneum, which covers its anterior surface and sides, its posterior surface being connected by loose areolar tissue with the iliacus, quadratus lumborum, aponeurotic origin of transversus abdominis, and with the front of the lower and lateral part of the right kidney.
24.
There is a common set of layers covering and forming all the walls : the deepest being the parietal peritoneum, the extraperitoneal fat, the transversalis fascia, the internal and external oblique and transversus abdominis aponeuroses, and a layer of fascia, which has different names according to what it covers ( e . g ., transversalis, psoas fascia ).
