Arrangement of the collagen and elastic fibers in the upper human duodenum.

The arrangement of the elastic and collagen fibers in the upper human duodenum was examined. These fibers lie parallel to the muscle fibers in the tunica muscularis. In the submucosa they form a pantographic network arrangement, the cross-over angles of which increase in the oro-aboral direction. The collagen and elastic fibers show a polar orientation among the muscle fibers.