MARKSCHEIDENDICKE UND ACHSENZYLINDERDURCHMESSER IN PERIPHEREN MENSCHLICHEN NERVEN

Abstract

The author has measured the total diameter and the thickness of the axon in fibers taken from 3 motor and 3 cutaneous nerves of the limbs, the vagus and the white ramus communicans of T 5; 300 fibers from each nerve were measured. The measurements were done in silver-impregnated horizontal sections (in one nerve also with Weigert''s staining method), in teased preparations examined in polarized light, and in preparations stained with osmic acid. The average relation of axon diameter to total diameter ([image] = g) was found to be constant in all the myelinated fibers examined, regardless of their thickness; in the teased preparations and with Weigert staining g was about 0.50, with silver-impregnation about 0.47, which may be ascribed to greater shrivelling of the axons in the latter preparations. The limiting values of g in the myelinated fibers are about 0.70 and 0.30; this definitely makes them as a group on their own, quite distinct from the unmyelinated fibers. The fibers in the silver-impregnated preparations showed a shrivelling of 40%, those stained by the Weigert method of 20-25%, in comparison with fibers in fresh preparations.