1、Nervous tissue,高 志 华,教学要求,1、 熟悉神经组织的组成。2、了解神经胶质细胞的分类与功能。3、掌握神经元的形态结构、分类及突触的结构。4、熟悉神经纤维的概念、无髓神经纤维与有髓神经纤维的区别。5、熟悉神经末梢的概念、分类 与功能。6、掌握血脑屏障的含义。,An outline,NeuronsStructureSomaProcesses (neurites)Function Neuron-neuron communication (synapses)ClassificationMorphologytransmitterGlial cellsClassificationFun
2、ction,The most fascinating structure in the world-brain!Consists of nervous tissue,Components:nerve cells: neuron, 1012 neurons in the human brain Glial cells: neurogliaAstrocytesOligodendrocytesMicrogliaSchwans cellsFunction: Neurons: sense, receive, process information, initiate and conduct the ne
3、rve impulseGlial cells: support, protect, insulate and nourish neurons,Components of nervous tissue,Neuron 神经元,The structural and functional cellular unit,By Ramon Cajal,cell body (soma), 5 um-150umspherical, pyramidal fusiform stellate in shape, Processes (neurites)dendrites: like branches of treea
4、xon: long thin cord-liked process,Structure of neurons: morphology,Cell membraneunit membrane-excitability, to receive stimuli, initiate and conduct nerve impulsemembrane proteins- rich in ion channels and receptors,Structure of neurons-the soma,cell nuclei large and round, centrally- located, less
5、heterochromatin, so pale stained, with a large, clear nucleolus核：位于胞体中央，核大而圆，核仁明显。染色质细小呈松网状。,Structure of neurons-the soma,cytoplasm: a.k.a.perikaryon (核周质)General structures:MitochondriaLysosomeGolgi complexCentromereSpecial structuresNissl body （尼氏体）Neurofibril (神经原纤维) Lipofuscin (脂褐素),Structure o
6、f neurons-the soma,Nissl body (尼氏体),StructureLM: basophilic granulesEM: parallel arrays of RERs and free ribosomesfunction: Protein synthesis structural proteinsenzymes required for the production of neurotransmittersneuromodulators,LM：硝酸银染色可见 EM：神经丝、神经微管 功能：维持细胞形态支持 和运输物质,Neurofibril 神经原纤维,Golgi ap
7、paratusmitochondrialysosomes,Lipofuscin,Other organelles,Structure of neurons-the processes,Dendrites 树突: like branches of treeinformation input 1）一条以上并分枝2）表面粗糙有树突棘,3）接受刺激传导冲动到胞体。 Axon 轴突: long thin cord-liked processinformation output1）一条，分支少，常在末端呈直角分出2）轴丘(axon hillock)，无尼氏体，有神经原纤维3）传出冲动。,Axon,Dend
8、rites,Axon terminals,Dendrites 树突,many, short and more branchesContents: similar to the cell bodyfunction: receive informationdendritic spines (树突棘) places for synapse formation Increase the surface volume,thin, less branch，the longest axon（siatic nerve） can reach 1mno Nissl bodyhave microtubules, n
9、eurofilaments, microfilaments, mitochondria, SER and vesiclesaxon hillock 轴丘: the initiating part of axon(no Nissl body)Axolemma 轴膜: membrane on the axon surfaceAxoplasm 轴浆：plasma within the axonAxon terminal-function: To initiate and conduct the impulse,axon hillock,Axon 轴突,Information flow through
10、 neurons,slow anterograde 慢速轴突运输: cytoskeletal protein: microtubule, microfilament and neurofilament (0.1-0.4mm/d)细胞骨架结构（神经丝、神经微管）fast anterograde 快速顺向: synaptic vesicles, enzymes and proteins(100-400mm/d)轴膜更新所需的蛋白质、酶和神经递质fast retrograde 快速逆向: products of metabolism, intaking materials including pro
11、tein or neurotrophic factors (100-400mm/d)代谢产物，终末摄取物质,Axonal transport 轴突运输,Axonal transport,According to the number of processes 按突起分 multipolar neuron bipolar neuron pseudounipolar neuron中枢突外周突,Classification 神经元分类,According to function 按功能分sensory neuronmotor neuroninterneuron,Classification 神经元分
12、类,-According to the neurotransmitter 按递质分 cholinergic neuron aminergic neuron peptidergic neuron aminoacidergic neuron,Classification 神经元分类,-According to the length of axon Golgi type I neuron: long axon and large Golgi type II neuron: short axon,Classification 神经元分类,3. Synapse 突触,definition: the ju
13、nctions between neurons or neuron and non-nerve cells神经元与神经元之间、神经元和效应细胞（肌细胞、腺细胞）之间的一种特化的细胞连接，是传递信息的重要结构classification: chemical synapse: taking neurotransmitter as communicating medium electrical synapse: gap junction,Synapse 突触,化学性突触:占多数形式轴-体突触轴-树突触轴-轴突触组成EM:突触前成分 突触间隙(15-30nm) 突触后成分,-structure of
14、chemical synapse: LM: in silver preparation, there are many bouton-liked structures on the surface of dendrites and cell body, called synaptic bouton,EM: presynaptic element: axonal terminal presynaptic membrane synapse vesicle: -round or flattened, 40-60nm -clear or with electron dense coresynaptic
15、 cleft: 15-30nmpostsynaptic element: postsynaptic membranereceptors,Classification of chemical synapse: According to function: excitatory synapse inhibitory synapse,4. Glial cell (neuroglia)神经胶质细胞,神经胶质细胞,神经胶质细胞,神经胶质细胞,神经胶质细胞(neuroglial cell),分布在神经细胞之间,数量多。功能:支持、营养、绝缘和形成隋鞘（一）中枢神经胶质细胞 星形胶质细胞 少突胶质细胞 小胶
16、质细胞 室管膜细胞（二）周围神经胶质细胞 神经膜细胞 卫星细胞,function of Glial cell in CNS supporting, insulating and repairing regulate the environment and movement of neuron secret neurotrophic factor: nerve growth factor, ciliary neurotrophic factor and glial cell line-drived neurotrophic factor,large stellateround or ovoid
17、nucleus, large and pale (euchromatin)glia filament: intermediate filamentend feet: to form glia limitans or vascular feet - constitute blood brain barrier,end feet,Astrocytes 星型胶质细胞,纤维性：多在白质，突起细长，表面光滑 ，胶质丝多 原浆性：多在灰质，突起短粗，表面粗糙，胶质丝少 构成血脑屏障的胶质膜,星形胶质细胞分类,protoplasmic 原浆性,fibrous 纤维性,Structure: smaller,
18、fewer process with a small round and dark stained N,Oligodendrocyte少突胶质细胞:,Function: To form myelin-sheath of NF in CNS,structure: smallest, elongate shape or ovoid, with a small dark irregular Nfunction: phagocytosis - mononuclear phagocyte system,Microglia小胶质细胞,structure: simple cuboidal or column
19、ar epiapical: microvilli and ciliabasal: long processesfunction: produce cerebrospinal fluidnerve stem cell in or under ependymadistribution: ventricle of brain and central canal of spinal cord,Ependymal cell 室管膜细胞,glial cell in PNS (peripheral nervous system),神经膜细胞(Schwann cell)：形成周围神经纤维的髓鞘。神经节胶质细胞
20、（卫星细胞）：神经节内包裹神经元胞体的胶质细胞，又称被囊细胞。,definition: a structure formed by axon and glial cell can conduct the impulse to certain direction-classification: according to myelin-sheath myelinated nerve fiber有髓神经纤维 unmyelinated nerve fiber无髓神经纤维,Nerve fiber 神经纤维,1) myelinated nerve fiber (MNF) MNF in PNSLM: Axo
21、nmyelin-sheath: HE: net-liked; OsO4(osmium tetroside) fixation and stain: black with Schmidt-Lantermann incisureneurilemma: cell membrane of Schwann and basement membrane,Ranvier node: narrow part, no myelin-sheath-saltatory conduction internode: the segment of NF between two Ranvier nodes,Ranvier n
22、odes,Axon,组成：轴突髓鞘神经膜神经胶质细胞周围：神经膜细胞 Schwann xbao中枢：少突胶质细胞,有髓神经纤维 myelinated nerve fiber,有髓神经纤维,组成：轴突髓鞘神经膜,有髓神经纤维与无髓神经纤维横切,神经（nerve）周围神经纤维束平行排列，外包结缔组织膜而成的索状结构。,神经外膜（epineurium）神经束膜（perineurium）神经内膜（endoneurium）,神经末梢(never ending),定义：周围神经纤维的终末部分终止于其 他组织中所构成的特殊结构。 分类： 感觉神经末梢 运动神经末梢,感觉神经末梢1.游离神经末梢：冷、热、痛2
23、.有被囊的感觉神经末梢：触觉小体 环层小体 肌梭运动神经末梢运动终板,游离神经末梢无髓腔而裸露部分。感觉冷热、疼痛等,被囊神经末梢触觉小体、环层小体、肌梭,运动神经末梢定义：运动神经元的轴突分布骨骼肌、平滑肌及腺内并与其他组织共同构成的结构分类： 内脏运动神经未梢 躯体运动神经未梢,内脏运动神经末梢,分布于心肌、平滑肌及腺细胞的植物神经未端分支，未梢形成串珠状或呈膨大小结。,躯体运动神经末梢（运动终板）支配骨骼肌，形成突触前膜、突触间隙、突触后膜。,血脑屏障（blood-brain barrier）,组成：连续毛细血管内皮基膜神经胶质膜功能：限制有害物质进入脑神经组织,LM: shown on
24、y by silver impregnation methods as a network formed thread-liked dark brown structures (2-3 um),Neurofibril,Love your cellsLove your tissuesLove yourselfLove histology!,LM: shown ony by silver impregnation methods as a network formed thread-liked dark brown structures (2-3 um),Neurofibril,axon,dendrite,
