ABSTRACT
Local anesthetics exert their action by blocking the flow of sodium ions through the cell membrane.3
Nerve fibers are divided into three groups (A, B, and C) based on size, function, and degree of myelinization.1 A-fibers are subdivided by decreasing size as alpha, beta, gamma, and delta. A-fibers are large myelinated fibers. A-alpha fibers have motor, proprioception, and reflex function. A-beta fibers have touch and pressure sensation functions. A-gamma fibers control muscle tone. A-delta fibers sense pain and temperature. B-fibers are myelinated preganglionic sympathetic fibers that manage vascular smooth muscle contraction. C-fibers are unmyelinated postganglionic fibers that sense pain and temperature.
