每一根运动神经元,及其所支配的骨骼肌纤维合称一个运动单位。一般说,越是精细的快速运动的肌肉,其中每个运动神经元所支配的肌纤维数目就越少,如眼外肌中,每个运动单位只包括10—15条肌纤维,而那些维持姿势的肌肉中,每个运动神经元所支配的肌纤维的数目比较多;可达到300—800条肌纤维。人体上的各个肌肉中均含有许多运动单位,当运动时,运动神经元接受高级中枢 Each motor neuron, and its dominated skeletal muscle fibers together referred to as a unit of motion. In general, the more elaborate, fast-moving muscles in which the number of muscle fibers per motor neuron dominates are less, as in the extraocular muscles, each motor unit contains only 10-15 muscle fibers, while those that maintain posture Muscle, motor neurons dominate the number of muscle fibers more; up to 300-800 muscle fibers. Each muscle in the body contains many units of exercise, when exercising, motor neurons to accept the senior center