ABSTRACT

The spleen represents the only lymphatic tissue specialized to filter the blood, and its microcirculation is probably the most complex of any organ in the body. Arteries and veins enter and leave the spleen along the hilus of its concave surface and pass within trabeculae into the interior of the organ. Unlike other organs studied from a microcirculatory standpoint, the spleen is not concerned with transcapillary exchange in relation to metabolism. Its two primary functions concern immunologic reactions and the filtration of cells and particulate matter from the blood. It has long been recognized that the spleen concentrates normal blood cells to twice arterial hematocrit, and harbors more than 30% of all circulating platelets in the body. The spleen is rarely the primary site of disease, but is affected by a wide range of disease processes originating elsewhere in the body. Microvascular corrosion casting may be applied to spleens of humans as well as laboratory animals.