Scanning Electron Microscopic Study of the Capillary Loops in Human Hand Skin
The microvasculature of the ball of the finger of an 85-year-old man was examined by means of scanning electron microscopy of resin casts. Each papilla had a loop of capillary vessels with ascending limbs, a hairpin turn and descending limbs. After the loop passed a hairpin turn, the descending limbs were 1.3 times larger than the ascending limbs. Three patterns of capillary loops were observed in this area: (1) a single loop pattern, with a straight or coiled structure, (2) a complex loop pattern, in which the capillary loops were formed out of not just one capillary vessels, but out of two or three vessels. Each capillary vessel arose and divided into several branches at the papillae and they became descending limbs, (3) an intermediate pattern between type (1) and (2). I believe that changes in the papillae due to aging cause these differences.