《感觉系统症状》PPT课件.ppt

感觉神经系统症状,郑州大学第一附属医院神经内科 苗 旺,General Properties of Sensory Systems,Figure 10-4: Sensory pathways,1. Sensory receptors,A: Free nerve endings (pain, temperature) B: Pacinian corpuscle (pressure) C: Meissners corpuscle (touch) D: Muscle spindle (stretch),Sensory Receptor Types,Figure 10-1: Sensory receptors,Ruffinis endings respond to tension and stretch in the skin,Segmental innervation (dermatomes) Peripheral innervation,感觉传导路由三级神经元组成： 第级神经元:胞体位于脊髓后根神经 节或脑神经感觉神经节 第级神经元:胞体位于脊髓后角细胞及延髓薄束核、楔束核或脑干脑神经核 第级神经元:胞体位于丘脑感觉接替核,Spinothalamic pathway,Carries pain, temperature, touch and pressure signals 1st neuron enters spinal cord through dorsal root 2nd neuron crosses over in spinal cord; ascends to thalamus 3rd neuron projects from thalamus to somatosensory cortex,2.浅感觉传导路: 前外侧系统 the anterolateral system (先交叉，后上行) 轻触-压觉,痛觉,温度觉的传入纤维 经后根节外侧部(细纤维部分) 进入脊髓后角并于此换元 换元后的第级神经元发出纤维 在中央管前交叉到对侧 沿脊髓丘脑前束、脊髓丘脑侧束 上行到达丘脑感觉接替核,Somatic Pathways,Figure 10-9: Sensory pathways cross the bodys midline,Spinothalamic Pathway,Small sensory fibres: Pain, temperature, some touch,Primary somatosensory cortex (S1),Thalamus,Medulla,Spinal cord,Spinothalamic tract,Impulses transmitted to spinal cord by Myelinated A nerves: fast pain (80 m/s) Unmyelinated C nerves: slow pain (0.4 m/s),Impulses ascend to somatosensory cortex via: Spinothalamic pathway (fast pain) Reticular formation (slow pain),Spinothalamic damage,请同学们屈起右腿 右手放在桌子上 闭上眼睛 按指令完成动作,2.2 Dorsal column pathway,Carries fine touch, vibration and conscious proprioception signals 1st neuron enters spinal cord through dorsal root; ascends to medulla (brain stem) 2nd neuron crosses over in medulla; ascends to thalamus 3rd neuron projects to somatosensory cortex,三者的传入冲动 经后根节外侧部(粗纤维部分) 进入脊髓后角 沿同侧后索上行 抵达延髓下部 在薄束核、楔束核换神经元 换元后的第级神经元发出纤维 交叉到对侧 沿内侧丘系 到达丘脑感觉接替核。,dorsal cloumn pathway,Dorsal column pathway,Large sensory nerves: Touch, vibration, two-point discrimination, proprioception,Primary somatosensory cortex (S1) in parietal lobe,Thalamus,Medulla,Medial lemniscus,Spinal cord,Dorsal column,Dorsal column nuclei,Two-Point Discrimination,Sensory Modality,Figure 10-3: Two-point discrimination,Sensory Modality,Figure 10-6: Lateral inhibition,Dorsal column damage,Dorsal column damage,Sensory ataxia Patient staggers; cannot perceive position or movement of legs Visual clues help movement,由于传导痛觉、温度觉的传入纤维在进入脊髓后在进入水平的 1-2个节段内更换神经元并交叉到对侧；而传导轻触(- 压)觉的传入纤维在进入脊髓后分成上行和下行纤维，分别在多个节段内更换神经元并交叉到对侧，因而发生上述痛、温觉受损而触觉保留现象。,3.头面部的感觉传导路： Facial sensory pathway,触觉、本体感觉的传入冲动 三叉神经主核、中脑核中继换元,痛觉、温度觉的传入冲动 三叉神经脊束核中继换元,发出第级纤维越至对侧三叉丘系丘脑后内侧腹核,Sensory syndromes 1.,Peripheral nerve: according to the distribution area of the affected nerve Polyneuropathy: glove stocking distribution, more pronaunced distaly, more on the lower extremities Dorsal root ganglia or radicular laesions: segmental, localised to dermatomes,Sensory syndromes 2.,Spinal cord: -complete cord lesion -hemisection of spinal cord : Brown Sequard syndrome -central cord lesion (Syringomyelia, dissociated sensory loss: loss of pain and temperature, preservation of proprioception) -posterior tract lesion (funicular myelosis: loss of proprioception, ataxia) -conus laesion (sensory loss of sacral area, “saddle anaesthesia) Brain stem: Wallenberg syndrome Thalamus: Dejerine Roussy syndrome (contralateral hemihypaesthesia, ataxia, pain) Sensory cortex: co