ABSTRACT
The integrity of the skin of the lower limb depends on its microcirculation, and ulceration is the end result of microcirculatory failure. Those responsible for treating leg ulcers should therefore have a working knowledge of the lower limb circulation, a subject that is best considered under three headings: microcirculation, arteries and veins. Note, however, that the anatomy of the lower limb arteries is well described in anatomical textbooks and there is no need for repetition here.
The dermal microcirculation consists of a network of arterioles, the rete subpapillae, or superficial plexus, from which capillaries loop into the dermal papillae and so approach the base of the epithelium, before passing back to a venous plexus which lies immediately below the rete subpapillae. This drains into a flat intermediate plexus in the middle of the reticular layer of the skin and this plexus further connects with a deep laminar venous plexus at the junction of the dermis and the superficial plexus. Arteriovenous anastomoses are common in the deeper layer of the dermis. Some (glomera) are surrounded by sphincter-like groups of smooth muscle and pursue a convoluted course.1 Capillaries are tubes lined by a single layer of polygonal or lanceolate epithelial cells, and exchange of oxygen and other metabolites takes place through the wall of these cells and across the walls of venules and arterioles.
