Abstract
The blood supply to the valves of the heart and great vessels was studied by the Coslett Nixon X-ray projection microscope. Vascularization was found in 16% of the cusps in the tricuspid valve, in 10% of the mitral cusps, and in 24% of the aortic and pulmonary cusps. A characteristic "hairpin" arteriolar pattern was described in the papillary muscles.