教案成果组织学

1、 组织胚胎学课件组织胚胎学课件 七年制英文医学班专用七年制英文医学班专用中国医科大学中国医科大学基础医学院基础医学院组胚组胚英文教学组英文教学组 Chapter 7 Nervous tissueNervous tissue 1. General description:-Components: nerve cell: neuronGlial cell: neuroglial-Function: Neurons : receive the stimulation, conduct the nerve impulseGlial cell: support, protect and insulate

2、, nourish neurons2.2. NeuronNeuron The structural and functional cellular unit1)shape of neuron: consists of cell body, dendrite and axon-cell body: spherical, pyramidal fusiform or stellate in shape, 5um-150um-dendrite: like branches of tree-axon: long thin cord-liked2) structure of neuron cell bod

3、y: -cell membrane: unit membrane-irritability, receive stimuli, initiate and conduct nerve impulsemembrane proteins-ions channel and receptor-cell nucleus: large and round, centrally- located, less heterochromatin, so pale stained, with a large, clear nucleolus-cytoplasm: perikaryon a. Nissl body: L

4、M: basophilic spot-liked or granule-liked structureEM: parallelly-arranged RER and free ribosomefunction: synthesis of proteinsstructural proteinenzymes related to the production of neurotransmitters b. Neurofibril: LM: in silver i m p r e g n a t i o n methods(silver prepar a t i o n ) , there are

5、many thread-liked dark b r o w n c o l o r structure to form a network.EM: neurofilament: 10 nm in diametermicrotubule: 25 nm in diameterfunction: supporting involving in intracellular transportation c. other organelleGolgi apparatusmitochondriapigment dendrite: -many, short and more branches-struct

6、ure: similar to cell body-dendritic spine( places for formation of synapse) and spine apparatus(structure formed by 2-3 layers SER)-function: receive the information axon: -thin, less branch-structure: no Nissl body, but have microtubule, neurofilament, microfilament, mitochondria, SER and vesicleax

7、on hillock: the beginning part of axonaxolemmaaxoplasm-function: initiate an impulse and conduct the impulse* axonal transports: slow anterograde: cytoskeletal p r o t e i n : m i c r o t u b u l e , microfilament and neurofilament (0.1-0.4mm/d)fast anterograde: synaptic v e s i c l e s , e n z y m

8、e s a n d proteins( 100-400mm/d)fast retrograde: products of metabolism, intaking materials including protein or neurotrophic factors(100-400/d)3) classification:-According to number of processes multipolar neuron bipolar neuron pseudounipolar neuron-According to length of axon Golgi type I neuron:

9、long axon and large Golgi type II neuron: short axon-According to function sensory neuron motor neuron interneuron-According to the neurotransmitter or neuromodulator release by the neuron cholinergic neuron aminergic neuron peptidergic neuron aminoacidergic neuron3. synapse3. synapse-definition: is

10、 the junctions between neurons or neuron and non-nerve cells-classification: c h e m i c a l s y n a p s e : t a k i n g neurotransmitter as communicating medium electrical synapse: gap junction-structure of chemical synapse: LM: in silver preparation, there are many button-liked structures on the s

11、urface of dendrites and cell body, called synaptic button EM: /presynaptic element: axonal terminal presynaptic membrane synapse vesicle: -round or flattened, 40-60nm -clear or with electron dense core -contain neurotransmitters: acetylcholine, Ach norepinephrine, NE dopamine, DA -neuromodulator: pe

12、ptides- change the reaction of neuron to neurotransmitter, modulate neurotransmitter substance P enkephalin vasoactive intestinal polypeptide, VIPthere are synapsin Imito, SER, microtubule and microfilament/synaptic cleft: 15-30nm/postsynaptic element: -postsynaptic membrane -receptorsClassification

13、 of chemical synapse: /According to function: excitatory synapse inhibitory synapse /According to structure: type I: postsynaptic membrane is thicker than presynaptic membrane, with wide synaptic cleft(excitatory synapse) type II: there are less electron dense material attached on synaptic m e m b r

14、 a n e , t h e t h i c k n e s s o f postsynaptic membrane is same to presynaptic membrane(symmetrical synapse)4. Glial cell(neuroglia)4. Glial cell(neuroglia) 1) Glial cell in CNS(central nervous system)a. Astrocyte: /large stellate /round or ovoid nucleus, large and pale (euchromatin) /gliafilamen

15、t: intermediate filament /end feet: to form glia limitans or vascular feet-constitute blood brain barrier /classification fibrous astrocytes: -white matter, have long, thin and smooth processes-more glial filament- glial fibrillary acidic protein, GFAP protoplasmic astrocyte: -gray matter, short, th

16、ick processes with more branch -less glial filament /function: .supporting, insulating and repairing ii. regulate the environment and movement of neuron iii. secret neurotrophic factor: nerve growth factor, NGF, ciliary neurotrophic factor, CNTP and glial cell line-drived neurotrophic factor, GDNFb.

17、 Oligodendrocyte: -structure: smaller, fewer process with a small round and dark stained N-function: i. their processes form myelin-sheath of NF in CNS ii. inhibite growth of processes of neuron( secrete inhibiting factor- NI-35,NI-250 myelin-associated glycoprotein)c. Microglia: -structure: smalles

18、t, elongate shape or ovoid, with a small dark irregular N-function: phagocytosis-mononuclear phagocyte systemd. Ependymal cell: -structure: simple cuboidal or columnar epiapical: microvilli and ciliabasal: long processes-tanycyte-function: produce cerebrospinal fluidnerve stem cell in or under epend

19、yma-distribution: ventricle of brain and central canal of spinal cord2) glial cell in PNS( peripheral nervous system) a. Schwann cell: /envelop the axon end to end to form myelin-sheath in PNS and /produce NGF, CNTF and BDNF(brain derived neurotrophic factor) b. Satellite cell (capsular cell): /one

20、layer of flattened or cuboidal cell, with round, ovoid and dark N /surrounding the Neuron in ganglion5. Nerve fiber and Nerve-definition: a structure formed by axon and glial cell can conduct the impulse to certain direction-classification: according to myelin-sheath myelinated nerve fiber unmyelina

21、ted nerve fiber 1) MNF MNF in PNSLM: Axonmyelin-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 segme

22、nt of NF between two Ranvier nodes EM: Schwann cell (neurilemmal cell) : Schwann cell invagination and envelop the axon form mesaxon mesaxon become longer and longer spiral around the fiber to force the N and cytoplasm go to two side, inner and out edges connecting with incisureMNF in CNS-structure:

23、 similar to in PNSmyelin-sheath formed by flattened ending of oligodendrocytes processesone oligodendrocyte can envelop many axonsno incisure and basement membrane 2) N-MNFN-MNF in PNS-structure: thin axon and Schwann cell connect end to endno myelin-sheath and Ranvier nodeone Schwann cell envelops

24、more axonsN-MNF in CNS * nothing to envelop the axon-naked axon 3) Nerve -Nerve fiber gets together to form nerve efferent N afferent N mixed N-structure: epineurium: DCT perineurium: -two layers: /outer layer- CT /inner layer-several layers of SSE- perineural epithelium(tight junction and basement

25、membrane) endoneurium: thin layer of LCT6. Nerve Ending6. Nerve Ending1) Sensory nerve ending-peripheral processes of pseudounipolar neuron + other structure to form sensory receptorfree nerve ending-structure: NFlose myelin-sheath branch distribute in epidermis, cornea, hair follicle epithelial cel

26、l and CT-function: feel cold, hot, pain and slight touch Encapsulated N ending -have CT capsule a. tactile corpuscle-structure: oval CT capsule flattened cell-transverse arranged NFlost myelin-sheathspiral flattened cells-distribution: dermal papillae, especially in tip of finger or toe, palms, sole

27、s and lips -function: touch receptors b. lamellar corpuscle-structure: large , oval or spherical capsule: several layers of flattened cell concentrically-arranged bulb- cylindrical NF lost MSenter the bulb-distribution: subcutaneous T, mesentery, ligament-function: feel deep or heavy pressurec. Muscular spindles-structure: fusi