[Location] With the thumb extended, on the radial side of the thumb, 0.1 cun distance from the comer of the nail ( Fig.4 )

[Regional Anatomy] Skin→subcutaneous tissue→the base of nail. The arterial and venous network formed by the palmar digital proprial nerve derived from the median nerve, and the arterial and venous network formed by the thumb's main artery and vein, and the branches of the palmar's first back artery and vein.