The superior part of the duodenum, as stated above, is somewhat movable, but the rest is practically fixed, and is bound down to neighboring viscera and the posterior abdominal wall by the peritoneum. In addition to this, the ascending part of the duodenum and the duodenojejunal flexure are fixed by a structure to which the name of suspensory muscle of duodenum (Suspensory ligament of duodenum; Musculus suspensorius duodeni ) has been given.
This structure commences in the connective tissue around the celiac artery (coeliacoduodenal part) and left crus of the diaphragm (phrenicocoeliac part), and passes downward to be inserted into the superior border of the duodenojejunal curve and a part of the ascending duodenum, and from this it is continued into the mesentery. It possesses, according to Treitz, plain muscular fibers mixed with the fibrous tissue of which it is principally made up. It is of little importance as a muscle, but acts as a suspensory ligament.