颈髓位于脊髓的最上端,是延髓的延续,延髓到脊髓是逐渐过渡的,其间并无明显的分界[1],在枕骨大孔水平转变为脊髓。颈髓分为8个节段(C1-8),为上、中、下3段,即颈上段(C1-3)、中段(C4-6)、下段(C7-8,T1),C4-T1形成颈膨大。延髓是呼吸循环的生命中枢并参与体温调节等多种生理功能, Cervical spinal cord at the top of the spinal cord is a continuation of the medulla oblongata to the spinal cord is a gradual transition in the absence of a clear boundary between [1], in the foramen magnum level into the spinal cord. The cervical spinal cord is divided into eight segments (C1-8), which are upper, middle and lower three segments, namely, upper cervical segment (C1-3), middle segment (C4-6), lower segment (C7-8, T1 form neck enlargement. Medulla is the life cycle of the respiratory cycle and participate in a variety of physiological functions such as thermoregulation,