感觉系统症状1ppt课件

1、觉得神经系统病症觉得神经系统病症郑州大学第一附属医院神经内科郑州大学第一附属医院神经内科苗苗 旺旺GENERAL PROPERTIES OF SENSORY SYSTEMSFigure 10-4: Sensory pathways1. SENSORY RECEPTORSA: Free nerve endings (pain, temperature)B: Pacinian corpuscle (pressure)C: Meissners corpuscle (touch)D: Muscle spindle (stretch)ABCDSENSORY RECEPTOR TYPESFigure 10

2、-1: Sensory receptorsRuffinis endings respond to tension and stretch in the skin SEGMENTAL INNERVATION (DERMATOMES)PERIPHERAL INNERVATIONSPINOTHALAMIC PATHWAYCarries pain, temperature, touch and pressure signals1st neuron enters spinal cord through dorsal root2nd neuron crosses over in spinal cord;

3、ascends to thalamus3rd neuron projects from thalamus to somatosensory cortex在中央管前交叉到对侧在中央管前交叉到对侧沿脊髓丘脑前束、脊髓丘沿脊髓丘脑前束、脊髓丘脑侧束脑侧束上行到达丘脑觉得接替核上行到达丘脑觉得接替核SOMATIC PATHWAYSFigure 10-9: Sensory pathways cross the bodys midlineSpinothalamic PathwaySmall sensory fibres:Pain, temperature, some touchPrimary somato

4、sensory cortex (S1)ThalamusMedullaSpinal cordSpinothalamic tractImpulses transmitted to spinal cord byMyelinated A nerves: fast pain (80 m/s)Unmyelinated C nerves: slow pain (0.4 m/s)nociceptornociceptorA nerveC nervespinothalamicpathwayto reticularformationImpulses ascend to somatosensory cortex vi

5、a:Spinothalamic pathway (fast pain)Reticular formation (slow pain)reticular formationspinothalamicpathwaythalamussomato-sensorycortexSPINOTHALAMIC DAMAGEspinothalamic pathwayLeftspinal cord injuryLoss of sense of:TouchPainWarmth/coldin right leg请同窗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 PATHWAYCarr

6、ies fine touch, vibration and conscious proprioception signals1st neuron enters spinal cord through dorsal root; ascends to medulla (brain stem)2nd neuron crosses over in medulla; ascends to thalamus3rd neuron projects to somatosensory cortexdorsal cloumnpathwayLarge sensory nerves:Touch, vibration,

7、 two-point discrimination, proprioceptionPrimary somatosensory cortex (S1) in parietal lobeThalamus MedullaMediallemniscusSpinal cordDorsal columnDorsal columnnucleiTWO-POINT DISCRIMINATIONSENSORY MODALITYFigure 10-3: Two-point discriminationSENSORY MODALITYFigure 10-6: Lateral inhibitionDORSAL COLU

8、MN DAMAGEdorsal column pathwayLeftspinal cord injuryLoss of sense of:touchproprioceptionvibrationin left legDORSAL COLUMN DAMAGESensory ataxiaPatient staggers; cannot perceive position or movement of legsVisual clues help movementSENSORY SYNDROMES 1.Peripheral nerve:according to the distribution are

9、a of the affected nervePolyneuropathy:glove stocking distribution,more pronaunced distaly, more on the lower extremitiesDorsal root ganglia or radicular laesions:segmental, localised to dermatomesSENSORY SYNDROMES 2.Spinal cord:-complete cord lesion-hemisection of spinal cord : Brown Sequard syndrom

10、e-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 syndromeThalamus: Dejerine Roussy syndrome (contralateral hemihypaesthesia, ataxia, pain)Sensory cortex: contrala