The morphogenesis of the vasculature in swine fetal skin

The morphogenesis of the vascular elements in the skin of 45 swine fetuses (German landrace), from 50 to 330 mm crown-to-rump (C-R) length, was described. A simple pattern for the cutaneous vascular networks could be recognized in fetuses ranging from 90 to 100 mm C-R length. In 150 to 170 mm length-fetuses, the cutaneous blood vessel networks were differentiated into a definite pattern of construction. The venous blood drained regionally through the Plexus venosus subpapillaris profundus into the Plexus venosus dermis profundus. Each region ("Unit Vascular Zone") was supplied by more than one R. arteriosus cutaneus . The large branches of R. arteriosus cutaneus were accompanied by 2 satellite veins. At the end of gestation, the vessels of the Plexus venosus dermis profundus exhibited a beaded appearance which indicated the presence of valves.