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1、The Nervous System,山东大学医学院 解剖教研室李振华,Divisions,Central nervous system(CNS)Peripheral nervous system(PNS),Central nervous system(CNS)Brain 脑Telencephalon 端脑Diencephalon 间脑Cerebellum 小脑Brain stem 脑干 Midbrain 中脑Pons 脑桥Medulla oblongata 延髓Spinal cord 脊髓,Peripheral nervous system(PNS)Cranial n.(12 pairs)脑
2、神经Spinal n.(31 pairs)脊神经Visceral n.内脏神经Visceral sensory n.Visceral motor nSympathetic part 交感神经 Parasympathetic part 副交感神经,Neurons 神经元 Cell body 胞体Axon 轴突Dendrites 树突 Neuroglia glial cell胶质细胞,Structural classificationBipolar neuron 双极神经元 has an axon and a dendritePseudounipolar neuron 假单极神经元 has a c
3、entral branch and a peripheral branchMultipolar neuron多极神经元has an axon and two or more dendritesFunctional classificationSensory(efferent)neuron 感觉神经元Motor(afferent)neuron 运动神经元Association neuron 联络神经元,Reflex:a reaction of the organism by the nervous system in response to a stimulusReflex arc:has 5
4、basic components Receptor Sensory neurons CNS Moter neurons Effector,Reflex and reflex arc,Basic terminology in nervous system,In the CNSGray matter 灰质:collection of nerve cell bodies and their dendrites,gray color during fresh conditionCortex皮质:the outermost layer of gray matter in cerebrum and cer
5、ebellumWhite matter白质:collection of nerve fibers,white color during fresh conditionMedulla髓质:a central core of white matter beneath cortex of cerebrum and cerebellumNucleus神经核:a collection(group)of cell bodies which have the same shape and function,Fasciculus 纤维束(tract):a bundle of nerve fibers whic
6、h have the same origin,termination,pathway and functionReticular formation 网状结构:an admixture of cross-crossing fibers with larger or smaller groups of nerve cells occupying the meshes,In the PNSGanglion 神经节:a collection of neuronal cell bodies outside the CNSNerve 神经:a bundle of nerve fibers held to
7、gether by connective tissue sheath,The Spinal Cord 脊髓,PositionLies in vertebral canalContinuous above with medulla oblongata at level of foramen magnum Ends below at lower border of L1 in adult;at birth at level of L3,External features,A long cylindrical structure and slightly flattened anteroposter
8、iorly,Conus medullaris（脊髓圆锥）Filum terminale（终丝）Cauda equina（马尾）Two enlargements Cervical enlargement（颈膨大）:corresponds to the C4 to the T1 segments Lumbosacral enlargement（腰骶膨大）:corresponds to the L2 to the S3 segments,Fissure and sulciAnterior median fissure 前正中裂Posterior median sulcus 后正中沟Anterolat
9、eral sulcus 前外侧沟anterior(motor)roots emerge serially Posterolateral sulcus 后外侧沟posterior(sensory)roots enter spinal cord,each bear a spinal ganglion which constitutes the first cell-station of the sensory nerves,Relationship of segments of spinal cord to vertebrae,A portion of the cord that gives ri
10、se to a pair of spinal nerve constitutes a segment.There are 31 segments 8 cervical 12 thoracic 5 lumbar 5 sacral 1 coccygeal,Relationship of segments of spinal cord to vertebrae,Internal structures,Central canal 中央管Gray matterAnterior horn(column)前角（柱）Posterior horn(column)后角（柱）Intermediate zone 中间
11、带Lateral horn(column)侧角（柱）Anterior gray commissures 灰质前连合Posterior gray commissures 灰质后连合White matterAnterior funiculus 前索lateral funiculus 外侧索Posterior funiculus 后索Anterior white commisure 白质前连合,Posterior horn(column):Marginal layer（缘层）Substantia gelatinosa（胶状质）Nucleus proprius（后角固有核）Nucleus thorac
12、icus（胸核）in segments C8L3,Intermediate zoneIntermediaolateral nucleus（中间外侧核）(lateral horn or column):lies in segments T1L3,containing sympathetic preganglionic neuronsSacral parasympathetic nucleus（骶副交感核）:lies in segments S2S4,containing parasympathetic preganglionic neuronsIntermediomedial nucleus（中
13、间内侧核）:for sensation of viscera,Anterior horn(column):contain motor neurons Three kinds of neuron-motor neuron:larger multipolar neuron,innervates extrafusal fibers of skeletal m.,producing contraction of m.-motor neuron:smaller neuron,innervates intrafusal fibers regulating muscular tonusRenshaws ce
14、ll:negative feedback mechanismTwo groups of nucleiMedial nuclear group:present in most segments of spinal cord,innervating axial musclesLateral nuclear group:present only in cervical and lumbosacral enlargements,innervating limb muscles,Rexeds lamina 板层,posterior horn is formed by lamina to；Intermed
15、iate zone corresponding to lamina；Anterior horn is composed laminae and；lamina is the gray matter surrounding the central canal.,Important Subdivision of Spinal Cord Gray Matter,)White matter,White matter contains three kinds of fibers:ascending,descending,and fasciculus proprius,Ascending tracts,Fa
16、sciculus gracilis（薄束）,Fasciculus cuneatus（楔束）,Posterior spinocerebellar tract（脊髓小脑后束）,Anterior spinocerebellar tract（脊髓小脑前束）,Spinothalamic tract（脊髓丘脑束）,Ascending tracts,Descending tracts,Lateral corticospinal tract（皮质脊髓侧束）,Anterior corticospinal tract（皮质脊髓前束）,Rubrospinal tract（红核脊髓束）,Vestibulospinal tract（前庭脊髓束）,Reticulospinal tract（网状脊髓束）,Medial longitudinal fasciculus（内侧纵束）,Tectospinal tract（顶盖脊髓束）,Fasciculus proprius（固有束）,Descending tracts,Main functions of spinal cord,Conduction of excitations Reflex activity,
