The microvasculature of the nail bed, nail matrix, and nail fold of a normal human fingertip

The organization of the microvasculature of the dorsal human fingertip based on a vascular corrosion cast was examined using a stereoscopic microscope. The variations of the superficial capillary network of the 3 specialized areas of skin of the dorsal fingertip (the nail bed, the nail matrix, and the nail fold) are described. In the nail bed numerous capillary loops were observed arising from a deeper regular arrangement of sagittally aligned, parallel rows of vessels. The size and direction of inclination of the capillary loops varied, getting longer and more inclined to the nail bed distally, with the longest capillary loops seen at the hyponychium. There were no capillary loops at the nail matrix region, but there was a single, layered, rectangular plexus of capillaries in the plane of the nail matrix. This extended distally to sagittally stretched coils of vessels that straightened out as the nail matrix enters the nail bed region. At the edge of the proximal nail fold the capillary loops looked like fine bristles and were approximately 3 times shorter than those found on the nail bed and hyponychium. This study provides a baseline for future work in understanding the changes in the microvasculature of the dorsal fingertip due to injury or pathology.