| 释义 |
脊髓jǐsuǐ人和脊椎动物中枢神经系统的一部分,在椎管里面,上端连接延髓,两旁发出成对的神经,分布到四肢、体壁和内脏。脊髓的内部有一个H形灰色神经组织,主要由神经细胞构成,外层为白色神经组织,由神经纤维构成。脊髓是许多简单反射的中枢。{spinal cord; part of the central nervous system of a human being and other vertebrates, which is found in the spinal canal and connects the medulla oblongata at its upper end. Pairs of nerves extend from the cord to the four limbs, body wall and internal organs. In the cross section, the spinal cord appears as a white oval with a grey, butterfly-shaped area in the centre. The white matter consists of myelinated (sheathed) fibres; the grey matter contains cell bodies, unsheathed motor-neurone fibres. The spinal cord is the centre of many simple reflexes.} |