組織胚胎學(xué)教學(xué)課件：四、神經(jīng)組織

1、Nervous tissue神經(jīng)組織第7章大綱要求1.掌握神經(jīng)元的結(jié)構(gòu)及功能；突觸的結(jié)構(gòu)及功能；神經(jīng)膠質(zhì)細(xì)胞的分類及功能。2.熟悉神經(jīng)元的分類；神經(jīng)纖維和神經(jīng)；神經(jīng)末梢的結(jié)構(gòu)及功能。特點(diǎn):神經(jīng)組織概述-神經(jīng)細(xì)胞 也稱神經(jīng)元，1012個(gè)， 功能: 具有接受刺激、整合信息和傳導(dǎo)沖動(dòng)的能力。 -神經(jīng)膠質(zhì)細(xì)胞 數(shù)量為神經(jīng)元的1050倍, 四種 (中樞神經(jīng)系統(tǒng)) 二種 (周?chē)窠?jīng)系統(tǒng)) 功能: 對(duì)神經(jīng)元起支持、保護(hù)、營(yíng)養(yǎng)和絕緣等作用。神經(jīng)元 H.E staining Silver stainingDifferent types of neurons Nucleus (核)Neuron H.ECell b

2、ody (胞體) Dendrite (樹(shù)突)Axon (軸突)一. 神經(jīng)元（一）結(jié)構(gòu)：1.胞體: 是神經(jīng)元營(yíng)養(yǎng)和代謝的中心（1）細(xì)胞核居中，大而圓，著色淺，核仁大而明顯（2）細(xì)胞質(zhì)特征： Neuron H.E high ampli.Nissl body 尼氏體Neurofibril 神經(jīng)原纖維Nissl body (尼氏體） LM: 強(qiáng)嗜堿性的的斑塊狀 或細(xì)顆粒狀結(jié)構(gòu)Nissl bodyNeuron H.E 功能:合成結(jié)構(gòu)蛋白;Neurotransmitter (神經(jīng)遞質(zhì))Neuromodulator (神經(jīng)調(diào)質(zhì))分布:胞體、樹(shù)突，軸丘和軸突內(nèi)無(wú)尼氏體分布TEM: Nissl body RER

3、 + free ribosome =尼氏體Neurofibril (神經(jīng)原纖維) LM: silver stain呈棕黑色細(xì)絲，交錯(cuò)排列成網(wǎng)neurofibrilNeuron Silver staining 功能:構(gòu)成神經(jīng)元細(xì)胞骨架；參與物質(zhì)運(yùn)輸EM: 神經(jīng)絲、微管、微絲 Transection of dendrite under TEM (樹(shù)突橫斷) (TEM: neurofilament + microtubule = neurofibril) 神經(jīng)絲 微管 神經(jīng)原纖維（3）細(xì)胞膜可興奮膜位于樹(shù)突/胞體: 具有接受刺激、處理信息的功能位于軸突：具有產(chǎn)生和傳導(dǎo)神經(jīng)沖動(dòng)的功能膜蛋白離子通道:

4、Na+、K+、Ca2+、Cl通道受體：突觸2. 樹(shù)突 Neuron H.EDendrite樹(shù)突Axon軸突功能：接受刺激，樹(shù)突和樹(shù)突棘擴(kuò)大了神經(jīng)元接受刺激的表面積形態(tài):一至多個(gè)樹(shù)突，形如樹(shù)枝狀，分支上?？梢?jiàn)大量短小的樹(shù)突棘3. 軸突只有一個(gè)軸突，一般比樹(shù)突細(xì)，無(wú)尼氏體，但有神經(jīng)原纖維分布軸丘：胞體發(fā)出軸突的部位常呈圓錐形，無(wú)尼氏體，染色淺功能：傳導(dǎo)神經(jīng)沖動(dòng)軸丘軸膜：the cytomembrane of axon軸質(zhì)：cytoplasm in axontransport of axon (軸突運(yùn)輸)：軸突內(nèi)的物質(zhì)運(yùn)輸軸突終末：the ends with numerous branchestel

5、odendria (軸突終末)Antergrade transport (順向軸突運(yùn)輸)Retrograde transport (逆向軸突運(yùn)輸)運(yùn)動(dòng)神經(jīng)元結(jié)構(gòu)模式圖（二）神經(jīng)元的分類1. 按神經(jīng)元突起的數(shù)量Multipolar neuron- 多極神經(jīng)元Bipolar neuron- 雙極神經(jīng)元Pseudounipolar neuron-假單極神經(jīng)元2. 按神經(jīng)元軸突的長(zhǎng)短Golgi typeneuron長(zhǎng)軸突 Golgi typeneuron短軸突Axon軸突（二）神經(jīng)元的分類3. 按神經(jīng)元的功能 Sensory neuron （afferent neuron） 感覺(jué)神經(jīng)元 Motor n

6、euron（efferent neuron）運(yùn)動(dòng)神經(jīng)元 Interneuron（connect neuron）中間神經(jīng)元nerve reflex arc 神經(jīng)反射?。ǘ┥窠?jīng)元的分類4. 按神經(jīng)元釋放的神經(jīng)遞質(zhì)和神經(jīng)調(diào)質(zhì)的化學(xué)性質(zhì)Cholinergic neuron 膽堿能神經(jīng)元Amine neuron 胺能神經(jīng)元Peptide neuron 肽能神經(jīng)元Amino acid neuron 氨基酸能神經(jīng)元（二）神經(jīng)元的分類 Norepinephrine neuron 去甲腎上腺素能神經(jīng)元二. Synapse (突觸) 1. 突觸的概念Neuron - effector cellNeuron -

7、neuron神經(jīng)元與神經(jīng)元之間，或神經(jīng)元與效應(yīng)細(xì)胞之間傳遞信息的結(jié)構(gòu)稱突觸。2. 突觸的分類電突觸: 縫隙連接化學(xué)突觸: 神經(jīng)遞質(zhì)作為傳遞信息的媒介3. 類型軸-樹(shù)突觸 軸-棘突觸軸-體突觸4. 結(jié)構(gòu)LM:1. 細(xì)胞質(zhì) 2. 細(xì)胞核 3. 突觸 synaptic knob 突觸小體 Cell body Synaptic (synaptic knob) 突觸小體SEM:Presynaptic element突觸前成分Synaptic cleft 突觸間隙Postsynaptic element突觸后成分Presynaptic membrane:thick, cone dense processe

8、s 致密突起Synaptic vesicle: 突觸小泡neurotransmitter/neuromodulator with synpsin (突觸素）15 30 nmPostsynaptic membrane:receptor and ion channelTEM:Mit. microfilament and microtubule 突觸超微結(jié)構(gòu)模式圖突觸電鏡圖Synaptic vesiclePresynaptic membraneSynaptic cleftPostsynaptic membrance（一）Neuroglial in CNS2.Oligodendrocytes 少突膠質(zhì)

9、細(xì)胞4. Ependymocyte室管膜細(xì)胞3.Microglia小膠質(zhì)細(xì)胞1.Astrocyte星形膠質(zhì)細(xì)胞三. Neuroglial cell (神經(jīng)膠質(zhì)細(xì)胞) protoplasmic astrocytemicrogliaoligodendrocytefibrous astrocyteNeuroglia in CNS1. 星形膠質(zhì)細(xì)胞星形-shaped cells with a large, oval nucleus. Glial filament-glial fibrillar acidic protein (GFAP) 膠質(zhì)絲 膠質(zhì)原纖維酸性蛋白形態(tài)： support and com

10、partmentalization (隔離作用） end feet-腳板（blood-brain barrier) glial limitans-膠質(zhì)界膜 secreting neurotrophic factor-神經(jīng)營(yíng)養(yǎng)因子功能: 原漿性星形膠質(zhì)細(xì)胞形態(tài): numerous shorter, thicker and more branched processes;relatively fewer glial filaments in cytoplasm 膠質(zhì)絲少Location: grey matter of CNS纖維性星形膠質(zhì)細(xì)胞形態(tài): long, thin, smooth and l

11、ess branched processes;more glial filaments in cytoplasm 膠質(zhì)絲多Location: white matter of CNS培養(yǎng)的星形膠質(zhì)細(xì)胞 免疫細(xì)胞化學(xué)（熒光素標(biāo)記）示膠質(zhì)原纖維酸性蛋白陽(yáng)性2. 少突膠質(zhì)細(xì)胞pyriform/oval nucleus ; fewer processes; smaller than astrocytes形態(tài):Function: form myelin 髓鞘Location: grey matter and white matter3. 小膠質(zhì)細(xì)胞： 血液?jiǎn)魏思?xì)胞形態(tài):Function: 神經(jīng)系統(tǒng)損傷時(shí)，

12、轉(zhuǎn)變?yōu)榫奘杉?xì)胞，吞噬死亡細(xì)胞的碎屑Smallest glia-ovoid with small , black nucleus and tortuous processesLocation: grey matter and white matter4. 室管膜細(xì)胞 cilium long processes 纖毛 形態(tài): 單層立方上皮 ; with microvilli and cilia at free/apical surface; with long, branched processes at basement membrane Location: the ventricles of

13、the brain and the central canal of the spinal cordFunction: involving in the production of cerebrospinal fluid (腦脊液）Left: microglia, Right: up - oligodendrocyte, down - protoplasmic astrocyte (siliver stain)（二） Neuroglial in PNS施萬(wàn)細(xì)胞衛(wèi)星細(xì)胞1. 施萬(wàn)細(xì)胞Morphology:Envelop the processes of neuronFunction: form

14、myelin2. 衛(wèi)星細(xì)胞扁平或立方形Function ：protection in a kind of cell capsule假單極神經(jīng)元Stellite cellMorphology：運(yùn)動(dòng)神經(jīng)元結(jié)構(gòu)模式圖脊髓運(yùn)動(dòng)神經(jīng)元光鏡圖神經(jīng)元中的神經(jīng)原纖維 (鍍銀染色)按神經(jīng)元的突起數(shù)量分三類：多極神經(jīng)元 雙極神經(jīng)元 假單極神經(jīng)元按神經(jīng)元的功能分為三類：感覺(jué)神經(jīng)元 運(yùn)動(dòng)神經(jīng)元 中間神經(jīng)元按神經(jīng)元軸突的長(zhǎng)短分為兩型：高爾基I 型神經(jīng)元 高爾基II 型神經(jīng)元按神經(jīng)遞質(zhì)和調(diào)質(zhì)的化學(xué)性質(zhì)分類：膽堿能神經(jīng)元 去甲腎上腺素能神經(jīng)元 胺能神經(jīng)元 氨基酸能神經(jīng)元 肽能神經(jīng)元神經(jīng)元的分類突觸電鏡圖Synaptic v

15、esiclePresynaptic membraneSynaptic cleftPostsynaptic membrance中樞神經(jīng)系統(tǒng)的神經(jīng)膠質(zhì)細(xì)胞：星形膠質(zhì)細(xì)胞少突膠質(zhì)細(xì)胞小膠質(zhì)細(xì)胞室管膜細(xì)胞周?chē)窠?jīng)系統(tǒng)的神經(jīng)膠質(zhì)細(xì)胞：施萬(wàn)細(xì)胞衛(wèi)星細(xì)胞神經(jīng)膠質(zhì)細(xì)胞：四. 神經(jīng)纖維和神經(jīng)（二）nerve（一）Nerve fiber神經(jīng)纖維：由神經(jīng)元的長(zhǎng)軸突及包繞它的神經(jīng)膠質(zhì)細(xì) 胞構(gòu)成分類：有髓神經(jīng)纖維無(wú)髓神經(jīng)纖維神經(jīng)：周?chē)窠?jīng)系統(tǒng)的神經(jīng)纖維集合在一起，構(gòu)成神 經(jīng)，分布到全身各器官 運(yùn)動(dòng)神經(jīng)元及神經(jīng)纖維結(jié)構(gòu)模式圖1. structure of myelinated fibers 有髓神經(jīng)纖維(1) Myeli

16、nated fibers in PNSLongitudinal section (LM)Left-H.E. Right-ideographLM:AxonSheath (segment)Ideograph of Myelinated fiberAxonSheathRanvier nodeinternodeThe node of RanvierThe internode (結(jié)間體）The nucleus of schwann cellThe incisure of schmidt-lantermann施-蘭切跡(1) Myelinated fibers in PNS 周?chē)窠?jīng)系統(tǒng)有髓神經(jīng)纖維Bas

17、ement memebrane1. inner cytoplasm2. sheath3. outer cytoplasm4. axonTEM:axonnucleus4axonsheath123axonsheaththe incisure of schmidt-lantermannNerve fiberRanvier nodeRanvier nodeaxonsheathosmium tetroxide fixed and stainH.E stainmyelinated fibers: Longitudinal section and transectionSheathRanvier nodeC

18、hemical composition:Myelin 髓磷脂 (80% lipoid+protein）？(2) Myelinated fibers in CNS 中樞神經(jīng)系統(tǒng)有髓神經(jīng)纖維Feature： Oligo.-sheath One cellmore axon2. Non myelinated fibers 無(wú)髓神經(jīng)纖維(1) Feature in PNS(2)Feature in CNS No sheath and nude axonMore axon(thin) + one schwann cellNo sheath and node 五. Nerve ending 神經(jīng)末梢What

19、 is the nerve ending?the ending of PNF周?chē)窠?jīng)纖維的終末，遍布全身分類：感覺(jué)神經(jīng)末梢游離神經(jīng)末梢、 觸覺(jué)小體、 環(huán)層小體、 肌梭運(yùn)動(dòng)神經(jīng)末梢軀體運(yùn)動(dòng)神經(jīng)末梢（運(yùn)動(dòng)終板）、 內(nèi)臟運(yùn)動(dòng)神經(jīng)末梢五. Nerve ending 神經(jīng)末梢（一）Sensory nerve ending 感覺(jué)神經(jīng)末梢Unencapsulated endings：free nerve endingEncapsulated endings:Tactile corpuscles 觸覺(jué)小體Lamellar corpuscles 環(huán)層小體Muscle spindle 肌梭（一）Sensory e

20、ndingsUnencapsulated endingsEncapsulated endingsTactile corpusclesLamellar corpusclesMuscle spindle1. Unencapsulated endings : 表皮、角膜、毛囊 冷、熱、輕觸、痛 Tactile corpuscles 觸覺(jué)小體Location: papilla 真皮乳頭層Function：touch 觸覺(jué)2. Encapsulated endings3. Lamellar corpuscles 環(huán)層小體Location: hypodermis 皮下組織Function: deep and heavy pressure receptor and detect vibration 壓覺(jué)、振動(dòng)覺(jué)4. Muscle spindle 肌梭Location: skeleton muscle 骨骼肌 Function: 本體感受器 肌梭光