系统解剖学-脊髓课件.ppt

上 、下运动神经元损伤综合征比较   上运动神经元综合征 下运动神经元综合征 瘫痪特点 痉挛性瘫（硬瘫） 弛缓性瘫（软瘫） 瘫痪范围 范围广泛 范围局限 肌张力 增 高 降 低 肌萎缩 无，晚期有废用性萎缩 早期出现 深反射 亢 进 减弱或消失 浅反射 减弱或消失 病理反射 有 无 * * * Spinal Cord Specimen. (Image modified from N.B. Everett, Functional Neuroanatomy. Lea Febiger 1971, with permission of Williams Wilkins). This is a posterior (dorsal) view of the caudal cervical cord enlargement (at about C7 or C8) and the upper thoracic cord. The dura has been reflected (and the arachnoid removed) to reveal the cord. Note that the posterior (dorsal) rootlets (the root itself is hidden beneath the dura at the dorsal root ganglion) form an almost continuous line of rootlets in the dorsolateral (posterolateral) sulcus. The dorsomedian (posteromedian) sulcus marks the division between left and right halves of the cord. The cuneate and gracile fasciculi can be seen on the surface; they are bundles of axons running longitudinally, that together make up the posterior funiculus (white matter). The denticulate ligaments are extensions of pia that anchor the cord laterally to the dura. Although they develop at each segmental level, they may appear irregularly-placed in the adult. * Spinal Cord Meninges. (Image modified from H.D. Patton et al., Introduction to Basic Neurology, with permission of W.B. Saunders Co., 1976). The meninges in this schematic are color-coded: dura (green), arachnoid (violet), and pia (yellow). The dura and arachnoid have been partially reflected to show underlying structures. The pia is closely applied to the cord itself and cannot be easily removed. Extensions of the pia form the denticulate ligament, which anchors the cord to the dural sheath laterally. At the caudal end of the cord (the conus medullaris), the filum terminale (another pial structure-not shown) anchors the cord to the caudal end of the dural sheath. The 3 meningeal layers extend out to the dorsal root ganglia, where they fuse imperceptibly with the connective tissue layers assoc