In textbooks on anatomy, radiology and stead of the normal one. An "accessory ar- surgery only the "normal" arterial blood tery" is a second artery ip addition to the one normally present, without any specifi- supply is usually described. This "nor- mality", however, is sometimes found in cation of size being made. However, there less than 30% of all cases for some arteries, is no general agreement on whether minute but in over 95% for others. Rarely men- vessels with very small diameters and hard- tioned are deviations in the individual ar- ly any significant blood flow should also be tery's origin, topographical localization and considered. the area it supplies. They can be classified The aims of this book were twofold: first, to into two groups: malformations and vari- extract the frequency of arterial anomalies from the literature (often published in inac- ations. Malformations often have a nega- tive influence on the function of the organ cessible journals) and second, to classity under normal circumstances, e.g. if both these arteries by schematic outlines of the basic types.
