(10.1)--10AnimalAnatomy-TheNervousSystem.pdf
Chapter 10 The Nervous SystemNervous TissueNervous tissueNeuronNeurogliocytePictures from the networkNeuronNeuronCytonProtuberanceCell nucleusCytoplasmCytomembranePictures from the networkProtuberanceProtuberanceDendriteAxonPictures from the networkThe Classification of NeuronsThe classification of neuronMultipolar neuronBipolar neuronPseudounipolar neuronPictures from the networkNeurogliocyteFunction:The function ofneurogliocyte is to support,nourish,protect,repair andform the myelin sheath.Pictures from the networkNeurogliocyteNeurogliocyteAstrocyteMicrogliaOligodendrocyteEpendymocyteSchwann cellSatellite cellPictures from the networkNervous SystemNervous systemCentral nervous systemBrainPictures from the networkSpinal cordPeripheral nervous systemShape of Spinal CordShape:The spinal cord is white inappearance,and its back-abdomenslightly flat long cylinder.Spinal cordCervical spinal cordThoracic spinal cordLumbar spinal cordSacral vertebra spinal cordCoccygeal vertebra spinal cordShape of Spinal CordThe spinal cord located at the backof the cervical spinal cord and thefront of the thoracic spinal cord iscalled cervical enlargement,fromwhichthespinalnervesaredistributed in the forelimbs.Shape of Spinal CordThespinalcordlocatedbetween the lumbar sacral pulpis called lumbar dilatation,which sends out spinal nervesin the pelvis and hind limbs.Shape of Spinal CordAfter lumbar enlargement,the spinal cordgradually narrows into a conical shape,called the conus medullaris.The filament after the conus medullaris iscalledneuropodium,which is attachedto the dorsal side of the vertebral body ofthe coccyx and has the function of fixingthe spinal cord.Shape of Spinal CordThe conus medullaris and neuropodium are surrounded by thesacral vertebrae nerve and coccygeal nerve,the structure isknown as the cauda equina.Groove in SurfaceSurface of spinal cordDorsal median sulcusVentral midline crackDorsolateral sulcusVentrolateral sulcusVentral midline crackVentrolateral sulcusInternal Structure of the Spinal CordThe internal structure of thespinal cord is a central tube withalong,slenderlongitudinalwalk in the center.The central tube is surroundedby gray matter,and the graymatter is surrounded by whitematter.Grey Matter of Spinal CordPosition:The gray matter isseen in the transverse section ofthe spinal cord，in the shape ofa butterfly.The dorsal projection of graymatter is called the dorsal horn,and the ventral projection iscalled the ventral horn.Grey Matter of Spinal CordThere is a shallow bulge at thebase of the ventral horn on theoutside of the gray matter in thethoracic and lumbar spinal cordcalled lateral horn.Grey Matter of Spinal CordGrey matterDorsal horn-Dorsal columnLateral horn-Lateral columnVentral horn-Ventral columnGrey Matter of Spinal CordThe gray matter that connectsthe left and right sides aroundthe central canal is calledgray commissure.Grey Matter of Spinal CordStructure:The gray matter of spinal cord is composed of alarge number of neuron bodies,a small number of nerve fibersand glial cells.Grey Matter of Spinal CordIn the dorsal column,it is mainly the cell body of interneurons.Grey Matter of Spinal CordOn the inner side of the ventral column are the cell bodies ofmotor neurons.Grey Matter of Spinal CordThe lateral column of thoracolumbar spinal cord is the cellbody of sympathetic preganglionic neurons.Grey Matter of Spinal CordIn the middle lateral column of the sacral spinal cord are thecell bodies of parasympathetic preganglionic neurons.Layering of the Grey MatterI layer-Marginal nucleus of dorsal hornII layer-Gelatinous substanceIII&IV layer-Nucleus propria dorsiV layer-Interneurons,located in theneck of dorsal hornVII layer-Intermediate zoneVIII&IX layer-Anterior hornX layer-Around the central tubeVI layer-Basal part of dorsal horn,onlyseenincervicalandlumbarenlargementWhite Matter of Spinal CordThe white matter is bright white,on thesurface of the spinal cord,surroundingthe gray matter.White matterDorsal funiculusLateral funiculusVentral funiculus White Matter of Spinal CordThe dorsal funiculus is thewhitematterbetweenthedorsal median sulcus and thedorsolateral sulcus.The lateral funiculus is thewhitematterbetweenthedorsolateral sulcus and theventrolateral sulcus.White Matter of Spinal CordThe ventral funiculus is thewhitematterbetweentheventrolateralsulcusandtheventral median fissure.Structure:The white matter ismainly composed of nerve fibers,which is the conduction pathwayof the spinal cord.Lateral FuniculusInjuries to the lateral ventrolateral funiculus can lead to sensoryand motor disorders and some muscle paralysis.White Matter of Spinal CordThe white matter is bright white,on thesurface of the spinal cord,surroundingthe gray matter.White matterDorsal funiculusLateral funiculusVentral funiculus the Function of the Spinal CordFirst：It transmits nerve impulses through the upper and lowerfiber bundles.the Function of the Spinal CordSecond：It completes reflexes through neuronal connectionswithin the spinal cord.MeningesMeningesSpinal pla materSpinal dura materIt is a three-layered connective tissuemembrane wrapped around the outsideof the spinal cord,collectively known asthe meninges.Spinal arachnoid materMeningesThe spinal pia mater is thinand contains abundant bloodvesselsandnervefibers,which are closely attached tothe surface of the spinal cordand protrude into the dorsalmediangrooveandthemedian fissure.MeningesThe spinal arachnoid mater is thinand transparent,forming a considerablespace between it and the pia mater,known as the subarachnoid space.The subarachnoid space communicatesanteriorly with the subarachnoid spaceof the brain and contains cerebrospinalfluid to nourish the spinal cord.MeningesThe space of subarachnoidspace between the lumbarspine or the sacrum withthe first caudal vertebra isenlarged.MeningesThereisawidespacebetween the spinal duraand the spinal canal calledthe epidural space.DiencephalonStructural features:The anterior end of the ventral side of thediencephalon is the optic chiasm,the posterior end is the posteriormargin of the papillary body,and there is the ventriculus tertius inside.DiencephalonDiencephalonEpithalamusThalamusMetathalamusHypothalamusHypothalamusThe hypothalamus isan important center ofautonomic nerve andendocrineregulation,suchasthesatietycenter,feeding center,etc.Hypothalamus and feeding behaviorVentriculus TertiusThe ventriculus tertius is circular and surrounds interthalamicadhesion.Ventriculus TertiusThe ventriculus tertius is connected to the midbrain tubebehind,and the lateral ventricle is connected to the front by apair of interventricular foramen.Ventriculus TertiusThe ventral side of the ventriculus tertius forms a depressionand extends into the funnel.The parietal wall is the diaplex,which connects with the paraplexus through the anteriorinterventricular foramen.BrainThe posterior end is separated from thecerebellum bythe fissurae transversacerebri.The longitudinal fissure dividesthe brain into left and right cerebralhemisphere.The brain,or telencephalon,is located onthe anterior-dorsal side of the brainstem.BrainEach cerebral hemisphere includes the cerebralcortex,white matter,rhinencephalon,and basalnucleus.The bottom of the longitudinal fissure is atransverse broad fibreboard connecting the twocerebral hemisphere,it is the corpus callosum.Cerebral HemisphereCerebral hemisphereDorsolateral prefrontalFacies medialisFacies ventralisThe anterior part is the frontal lobe,which is themotor area.The lateral part is the temporal lobe,which is theauditory area.The posterior part is the occipital lobe，which is thevisuosensory area.The dorsal part is the parietal lobe,which is thegeneral sensory area.Facies MedialisOnthefaciesmedialisisthecingulate gyrus,which is located onthe dorsal side of the corpus callosumand surrounds the corpus callosum.The facies medialis is located withinthe longitudinal fissure of the brainandcorrespondstothefaciesmedialis of the contralateral cerebralhemisphere.Facies VentralisThe facies ventralis,also known as thebasal surface,constitutes the bulbusolfactorius，and is the cortex in thecerebral hemisphere that receives andconformity olfactory impulse.Facies VentralisFacies ventralisBulbus olfactoriusOlfactory tractOlfactory gyrusOlfactory trigonePyriform lobeHippocampusDentate gyrusInternal Structure of the Cerebra HemisphereThe surface of the cerebral hemispheres on both sides is coveredwith the cerebral cortex,and the deep surface of the cortex is whitematter,which is composed of various nerve fibers.Equine brainInternal Structure of the Cerebra HemisphereThere are some gray matter masses in the basal part of the brain,called the basal nucleus(corpus striatum).Bovine brainInternal Structure of the Cerebra HemisphereEach cerebra hemisphere has a lumen called the lateralventricle.Bovine brainNuclei BasalesThe nuclei basales is the subcorticalmotor center,located deep in theolfactory triangle and at the base oftheanteriorpartofthelateralventricle.Nuclei basalesCaudate nucleusLenticular nucleusClaustrumNuclei BasalesFunction:Thebasalnucleus,which is regulated by the thalamusand cerebral cortex and sends outfiberstotherednucleusandsubstantia nigra,is the main contactpoint of the extrapyramidal systemand plays a role in maintainingmuscle tension and coordinatingmuscle movement.White MatterThe white matter in the cerebral hemisphere consists of thefollowing three fibers.Association fiberCommissural fiberProjection fiberWhite MatterThe commissural fibers are the fibers connecting the left andright cerebral hemispheres,mainly the corpus callosum.Association fiberCommissural fiberProjection fiberWhite MatterThe association fiber are the fibers connecting the gyrus andlobes of the ipsilateral hemisphere.Association fiberCommissural fiberProjection fiberWhite MatterThe projection fibers are the upper and lower fibers connectingthe cerebral cortex with other parts of the brain and the spinal cord.Association fiberCommissural fiberProjection fiberParaceleThe lateral ventricles are irregular cavities in each hemisphere ofthe brain and communicate with the ventriculus tertius throughthe interventricular foramen.ParaceleThe medial wall of the lateral ventricle is the septum pellucidum,located between the corpus callosum and the fornix.ParaceleThe parietal wall of the lateral ventricle is the corpus callosum,theanterior part of the basal wall is the caudate nucleus,and theposterior part is the hippocampus.Limbic SystemLimbic systemHippocampusPyriform lobeNuclei basalesAmygdalaNucleus anterior thalamicMeninges and Cerebrospinal FluidThe outer surface of the brain has three membranes:the duramater,the arachnoid mater,and the pia mater.VentricleVentricleParaceleVentriculus tertiusMesencephalic aqueductVentriculus quartus cerebriVentricleThe aqueduct of the midbrainconnects the third and fourthventricles.Theventriculustertiussurroundstheinterthalamicadhesions of the diencephalon.VentricleCerebrospinal fluid is a colorlesstransparent fluid produced by thechoroidplexusofthelateralventricle,the third ventricle,andthe fourth ventricle.The fourth ventricle is located inthe rhombencephalon and extendsback into the central canal of thespinal cord.VentricleThe cerebrospinal fluid in thesubarachnoid space passes throughthe dural sinus and into the vein.Cerebrospinalfluidfillstheventricle and the central canal ofthe spinal cord，and enters thesubarachnoid space through thechoroidplexusofthefourthventricle.Peripheral NervousBy functional characterMotor(efferent)nerveMixed nerveSensory(afferent)nervePeripheral NervousBy distributionSomatic nerveSplanchnic nerve（Vegetative nerve）Spinal nerveCranial nerveSympathetic nerveParasympathetic nerveSpinal NerveDorsolateral columnDorsalrootSpinal ganglionSpinal nerve（mixed nerves）Dorsal rootVentral branchVentral columnVentral rootSpinal GanglionPrior to the confluence of the dorsal and ventral roots of the spinalnerve,there is an enlargement,belonging to the sensory ganglion,which is mainly composed of the cell bodies of pseudounipolarneurons,known as the spinal ganglion.Spinal GanglionClassification of spinal nerves by locationCervical nerve8 pairsLumbar nerveSacral nerveCoccygeal nerve5 pairsThoracic nerveConsistent with vertebral numberSpinal GanglionDistribution of spinal nervesDorsal branchVentral branchPhrenic NerveThe phrenic nerve comes from the ventral branch of the 5th to 7thcervical nerve,distributed in the diaphragm.Intercostal NerveThe intercostal nerve consists of the ventral branches of the thoracicnerve,located in the intercostal space.Brachial PlexusThe brachial plexus consists of the ventral branches of the 6th to 8thcervical nerves and the ventral branches of the 1 and 2 thoracic nerves.Brachial PlexusMain branchSuprascapular nerveSubscapular nerveAxillary nervePectoral nerveMusculocutaneous nerveRadial nerveUlnar nerveMedian nerveBrachial PlexusThe brachial plexus reach themedial side of the shoulderjointanddividebranches,mainlydistributedinthemuscles,skin of the forelimbsand the lateral wall of thethoraco-abdominal cavity.Pectoral NerveThe pectoral nerve is divided intothe anterior pectoral nerve and theposterior pectoral nerve.Main distributionPectoralesThoracoabdominalcutaneous muscleSkinAxillary NerveThe axillary nerve originatesfrom the middle part of thebrachial plexus and crosses thegap between the subscapularisand teres major at the posterioredge of the shoulder joint.Axillary NerveMain distributionTeres majorDeltoidTeres minorMuscles of armMusculus subscapularisShoulder joint capsuleRadial NerveThe radial nerve is the largestbranch of the brachial plexus andis widely distributed.The radial nerve is distributed inall forelimb extensors except theshoulder joint.Ulnar NerveThe ulnar nerve and the median nerveoriginate from the posterior part of thebrachial plexus,and pass through thespace between the medial condyle of thehumerus and the olecranon into theulnar nerve groove behind the forearm.Ulnar NerveMain distributionFlexion wrist jointPhalangeal jointMedian NerveThe median nerve is the largest branch ofthe brachial plexus and is accompanied bythe brachial artery and the median artery.Main distributionFlexor carpi radialisFlexor digitorum profundusPhalangeal jointsMusculocutaneous NerveThemusculocutaneousnerveemerges from the middle part ofthe brachial plexus which behindthe subscapular nerve.Musculocutaneous NerveMain distributionBiceps brachiiMuscles of armForearmWristCapsula articularis cubitiSkin on the medial surface of the palmLumbosacral PlexusThe lumbosacral plexus is composedof the 4th to 6th lumbar nerve and theventral branch of the 1th to 2th sacralnerve,located at the ventral side ofthe lumbosacral region.Lumbosacral PlexusMain distributionFemoral nerveSciatic nerveObturator nerveAnterior gluteal nervePosterior gluteal nerveFemoral NerveThe femoral nerve originates fromthe anterior part of the lumbosacralplexus and extends backwards anddownwards between the psoas majorand psoas m
