Sx神经总论脊髓.pptx

第六篇 神经系统 Nervous system第1页/共60页Chapter 1 总论总论 Introduction Human nervous system is most Human nervous system is most complex anatomical and physical complex anatomical and physical system in body;it regulates and system in body;it regulates and integrates activities of all bodily integrates activities of all bodily systems for benefit of organism as systems for benefit of organism as a whole;and makes balance of a whole;and makes balance of external and internal external and internal environments in body.environments in body.基本要求基本要求基本要求基本要求 掌握神经系统的区分和常用术语。掌握神经系统的区分和常用术语。了解神经系统的组成。了解神经系统的组成。第2页/共60页I.神经系统的区分 Divisions of Nervous System中枢神经系统中枢神经系统central nervous central nervous system(CNS)system(CNS)周围神经系统周围神经系统Peripheral nervous Peripheral nervous system(PNS)system(PNS)按相连部位按相连部位按分布区分按分布区分按功能区分按功能区分 内脏神经的传出部分又称为自主神经系统或植物神经系统内脏神经的传出部分又称为自主神经系统或植物神经系统Autonomic nervous system Autonomic nervous system(交感神经交感神经 Sympathetic n.&Sympathetic n.&副交感神经副交感神经Parasympathetic n.)Parasympathetic n.)感觉感觉(传入传入)神经神经 Sensory(afferent)n.Sensory(afferent)n.运动运动(传出传出)神经神经 Motor(efferent)n.Motor(efferent)n.脑脑 BrainBrain脊髓脊髓 Spinal cordSpinal cord脑神经脑神经 Cranial n.(12 pairs)Cranial n.(12 pairs)脊神经脊神经 Spinal n.(31 pairs)Spinal n.(31 pairs)躯体神经躯体神经 Somatic n.Somatic n.内脏神经内脏神经 Visceral n.Visceral n.Visceral Visceral sensory n.sensory n.Visceral Visceral motor n.motor n.第3页/共60页II.神经系统的组成 Organization of Nervous Sys.Nervous system is composed of nervous tissue that consists Nervous system is composed of nervous tissue that consists of billions of nerve cells(neurons)and supported by a special of billions of nerve cells(neurons)and supported by a special variety of connective tissue known as neuroglia.variety of connective tissue known as neuroglia.I)I)神经元神经元 NeuronNeuron are independent structural unit of nervousare independent structural unit of nervoussystem and are functional system and are functional specialized for reception,specialized for reception,integration,and integration,and transmission of coded transmission of coded information.information.1.Structure of neuron1.Structure of neuron Each neuron possesses a Each neuron possesses a nucleated nucleated 胞体胞体 cell bodycell body第4页/共60页and two types of processes:an and two types of processes:an 轴突轴突 axonaxon conducts conducts impulse away from cell body,and one or more impulse away from cell body,and one or more 树突树突 dendrites dendrites conduct impulses towards cell body.conduct impulses towards cell body.Cell bodyCell body serves as metabolic center of entire serves as metabolic center of entire unit and consists of a large,pale nucleus and unit and consists of a large,pale nucleus and cytoplasm.Nucleolus occupies a prominent cytoplasm.Nucleolus occupies a prominent position in nucleus,which is rich in ribonucleic position in nucleus,which is rich in ribonucleic acid(RNA).acid(RNA).Organelles contained within cytoplasm are Organelles contained within cytoplasm are common to other cells in body,but there is abundant common to other cells in body,but there is abundant granular endoplasmic reticulum that constitutes granular endoplasmic reticulum that constitutes Nissl body(Franz Nissl,German nuerologist,Nissl body(Franz Nissl,German nuerologist,18601919),18601919),a protein synthesis apparatus.a protein synthesis apparatus.第5页/共60页 神经元构造 Structure of neuron第6页/共60页 2.Classification of neuron 2.Classification of neuron Neurons are classified according Neurons are classified according to their size,shape,function or by various other criteria.to their size,shape,function or by various other criteria.Structural classificationStructural classification depending on type and number of depending on type and number of their processes:their processes:双极神经元双极神经元 Bipolar neuron Bipolar neuron 假单极神经假单极神经元元 Pseudounipolar neuronPseudounipolar neuron(They has a central branch and a (They has a central branch and a peripheral branch);peripheral branch);多极神经多极神经元元 Multipolar neuronMultipolar neuron has an has an axon and two or more dendrites.axon and two or more dendrites.Functional classification:Functional classification:感觉神经元感觉神经元 Sensory(afferent)Sensory(afferent)neuron neuron 运动神经元运动神经元 Motor Motor(efferent)neuron(efferent)neuron 联络神经元联络神经元Association neuronAssociation neuron.第7页/共60页 神经元分类 Classification of neuron第8页/共60页 神经元分类 Classification of neuron第9页/共60页3.3.神经纤维神经纤维 Nerve fibersNerve fibers Longer processes of neuron Longer processes of neuron enveloped by myelin sheath and neurilemma are termed nerve enveloped by myelin sheath and neurilemma are termed nerve fibers.fibers.有髓纤维有髓纤维 Myelinated fibersMyelinated fibers are surrounded by a myelin are surrounded by a myelin sheath and neurilemma.sheath and neurilemma.无无髓纤维髓纤维 Unmyelinated fibersUnmyelinated fibers are are not,however,not,however,insulated by a myelin insulated by a myelin sheath.sheath.Oligodendrocytes Oligodendrocytes form myelin in central form myelin in central nervous system while nervous system while Schwann cells form Schwann cells form myelin in peripheral myelin in peripheral nerves.nerves.第10页/共60页 4.4.突触突触 SynapsesSynapses Within nervous system impulses are Within nervous system impulses are conducted from one part to another along a chain of neurons.conducted from one part to another along a chain of neurons.Terminal arborizations of axon of one neuron ramify in Terminal arborizations of axon of one neuron ramify in close contact with cell body or dendrites,less frequently with close contact with cell body or dendrites,less frequently with axonic terminals of many others.axonic terminals of many others.These structural and functional These structural and functional areas of contact are termed areas of contact are termed synapses.synapses.Each synapse involves close Each synapse involves close apposition of a presynaptic apposition of a presynaptic element with a postsynaptic element with a postsynaptic element from which it is separated element from which it is separated by a synaptic cleft.by a synaptic cleft.第11页/共60页 Presynaptic element contains numerous synaptic vesicles in Presynaptic element contains numerous synaptic vesicles in which chemical substance neurotransmitter is present.When which chemical substance neurotransmitter is present.When an impulse arrives at presynaptic element,neurotransmitter an impulse arrives at presynaptic element,neurotransmitter diffuses across synaptic cleft and binds to receptor molecules diffuses across synaptic cleft and binds to receptor molecules in postsynaptic membrane.As a result,postsynaptic neuron in postsynaptic membrane.As a result,postsynaptic neuron is activated and impulse is is activated and impulse is conducted from one conducted from one neuron to others.neuron to others.The“chemical The“chemical synapse”involving release synapse”involving release of transmitter substance is of transmitter substance is most common type in most common type in mammalian nervous sys.mammalian nervous sys.第12页/共60页 II)II)神经胶质神经胶质 NeurogliaNeuroglia Neuroglial cells outnumber neurons Neuroglial cells outnumber neurons in central nervous system 10:1.These cells appear to play a in central nervous system 10:1.These cells appear to play a number of important roles,including myelin formation,number of important roles,including myelin formation,guidance of developing neurons,maintenance of extracellular guidance of developing neurons,maintenance of extracellular K+levels,and reuptake of transmitters after synaptic activity.K+levels,and reuptake of transmitters after synaptic activity.1.1.星形星形胶质细胞胶质细胞 Astrocytes have many radiating processes,Astrocytes have many radiating processes,some of which end at nerve some of which end at nerve cells and others at capillaries.cells and others at capillaries.They are neuroectodermal in They are neuroectodermal in origin and may assist in origin and may assist in transfer of nutrients and transfer of nutrients and metabolic products between metabolic products between neurons and blood.neurons and blood.第13页/共60页 2.2.寡突胶质细胞寡突胶质细胞 OligodendrocytesOligodendrocytes are smaller and have are smaller and have fewer branching processes;they tend to lay in rows between fewer branching processes;they tend to lay in rows between nerve fibers and are concerned with production and nerve fibers and are concerned with production and nourishment of myelin sheaths especially those surround axon nourishment of myelin sheaths especially those surround axon in central nervous system.They are neuroectodermal in in central nervous system.They are neuroectodermal in origin.origin.3.3.小胶质细胞小胶质细胞 MicrogliaMicroglia are diminutive cells,which are diminutive cells,whichpermeate entire central permeate entire central nervous system.They are nervous system.They are modified macrophages modified macrophages and form part of reticulo-and form part of reticulo-endothelial system and endothelial system and are probably mesodermal are probably mesodermal in origin.in origin.第14页/共60页III.反射与反射弧 Reflex and Reflex Arc Reflexes are automatic,subconscious responses to stimuli Reflexes are automatic,subconscious responses to stimuli within or outside body.within or outside body.Reflex arc,a linkage of afferent and efferent neurons,is Reflex arc,a linkage of afferent and efferent neurons,is defined as entire neural pathway that is involved in a reflex.defined as entire neural pathway that is involved in a reflex.Reflex arc has 5 basic components:Reflex arc has 5 basic components:ReceptorReceptor Sensory Sensory neurons neurons CNS CNS Moter neurons EffectorMoter neurons Effector Interruption Interruption of this reflex of this reflex arc at any arc at any point abolishes point abolishes response.response.第15页/共60页ReceptorReceptor EffectorEffectorCentreCentreEfferentEfferentAfferentAfferent Reflex ArcInt,Ext EnvironmentHigher CentreHigher CentreResponses第16页/共60页IV.神经系统的常用术语 Basic terminology in nervous sys.In the CNSIn the CNS 灰质灰质 Gray matter Gray matter collection of nerve cell collection of nerve cell bodies and their dendrites,gray color during fresh bodies and their dendrites,gray color during fresh condition.condition.皮质皮质 Cortex matter Cortex matter outermost layer of gray outermost layer of gray matter in cerebrum and cerebellum.matter in cerebrum and cerebellum.白质白质 White matter White matter collection of nerve fibers,collection of nerve fibers,white color during fresh condition.white color during fresh condition.髓质髓质 Medulla matterMedulla matter a central core of white a central core of white matter beneath cortex of cerebrum and cerebellum.matter beneath cortex of cerebrum and cerebellum.第17页/共60页 Neuroanatomical terms in common usage 第18页/共60页 神经核神经核 Nucleus Nucleus a collection(group)of cell bodies which have same shape and a collection(group)of cell bodies which have same shape and function.function.纤维束纤维束 Fasciculus(tract)Fasciculus(tract)a bundle of nerve fibers which have the same origin,a bundle of nerve fibers which have the same origin,termination,pathway and function.termination,pathway and function.网状结构网状结构 Reticular formation Reticular formation an admixture of cross-crossing fibers with larger or an admixture of cross-crossing fibers with larger or smaller groups of nerve cells occupying the meshes.smaller groups of nerve cells occupying the meshes.第19页/共60页 In the PNSIn the PNS 神经节神经节 Ganglion Ganglion a collection of neuronal cell bodies outside the CNS.a collection of neuronal cell bodies outside the CNS.神经神经 Nerve Nerve a bundle of nerve fibers held together by connective tissue sheath.a bundle of nerve fibers held together by connective tissue sheath.第20页/共60页 Chapter 2 中枢神经系统中枢神经系统 Central Nervous Sys.Section 1 脊髓 Spinal Cord 基本要求基本要求 掌握脊髓的外形；脊髓灰质的分部、主要掌握脊髓的外形；脊髓灰质的分部、主要掌握脊髓的外形；脊髓灰质的分部、主要掌握脊髓的外形；脊髓灰质的分部、主要核团的名称、位置和功能；脊髓白质的分部，后核团的名称、位置和功能；脊髓白质的分部，后核团的名称、位置和功能；脊髓白质的分部，后核团的名称、位置和功能；脊髓白质的分部，后索和外侧索通过纤维束的名称和功能。索和外侧索通过纤维束的名称和功能。索和外侧索通过纤维束的名称和功能。索和外侧索通过纤维束的名称和功能。熟悉脊髓的位置；脊髓节与椎骨的对应关系；熟悉脊髓的位置；脊髓节与椎骨的对应关系；熟悉脊髓的位置；脊髓节与椎骨的对应关系；熟悉脊髓的位置；脊髓节与椎骨的对应关系；脊髓灰质的分层；前索通过的纤维束；脊髓的前脊髓灰质的分层；前索通过的纤维束；脊髓的前脊髓灰质的分层；前索通过的纤维束；脊髓的前脊髓灰质的分层；前索通过的纤维束；脊髓的前角、后角、白质前连和半离断时出现的症状或体角、后角、白质前连和半离断时出现的症状或体角、后角、白质前连和半离断时出现的症状或体角、后角、白质前连和半离断时出现的症状或体征。征。征。征。了解脊髓网状结构的位置；脊髓的功能。了解脊髓网状结构的位置；脊髓的功能。了解脊髓网状结构的位置；脊髓的功能。了解脊髓网状结构的位置；脊髓的功能。第21页/共60页 Spinal cord is about 18 inches(40 45 cmSpinal cord is about 18 inches(40 45 cm )long,1/2 inch)long,1/2 inch(14 mm)wide Lies in vertebral canal Continuous above(14 mm)wide Lies in vertebral canal Continuous above with medulla oblongata at levelwith medulla oblongata at levelof foramen magnum Ends of foramen magnum Ends below at lower border of L1 in below at lower border of L1 in adult;at birth at level of L3.adult;at birth at level of L3.It consists of centrally It consists of centrally located gray matter,involved located gray matter,involved in reflexes,and peripherally in reflexes,and peripherally located ascending and located ascending and descending tracts of white descending tracts of white matter that conduct impulses matter that conduct impulses to and from brain.to and from brain.第22页/共60页 I.I.脊髓的外形脊髓的外形 External featuresExternal features A long cylindrical structure and slightly flattened A long cylindrical structure and slightly flattened anteroposteriorly Two prominent enlargements can be seenanteroposteriorly Two prominent enlargements can be seenin a posterior view:in a posterior view:颈膨大颈膨大 Cervical enlargementCervical enlargement is located is located between C3 and T2 vertebrae between C3 and T2 vertebrae Nerves emerging from this Nerves emerging from this region serve upper extremities;region serve upper extremities;腰骶膨大腰骶膨大 Lumbar Lumbar enlargementenlargement lies between T9 lies between T9 and T12 vertebrae Nerves and T12 vertebrae Nerves from lumbar enlargement from lumbar enlargement supply lower extremities.supply lower extremities.第23页/共60页 Caudal to lumbosacral enlargement,spinal cord tapers Caudal to lumbosacral enlargement,spinal cord tapers gradually and becomes conical termination known as gradually and becomes conical termination known as 脊髓圆脊髓圆锥锥 conus medullarisconus medullaris.A condensation of pia mater forms.A condensation of pia mater forms 终丝终丝filum terminalefilum terminale that descends from conus medullaris to level of that descends from conus medullaris to level ofS2 vertebra;from here it is S2 vertebra;from here it is enveloped by dura mater and enveloped by dura mater and continues to posterior surface continues to posterior surface of coccyx.of coccyx.Some spinal roots surround Some spinal roots surround film terminale and extends film terminale and extends inferiorly referred to as inferiorly referred to as 马尾马尾 cauda equinacauda equina,because they,because they resemble a horses tail.resemble a horses tail.第24页/共60页 A longitudinal fissure and some sulci are shown on surface A longitudinal fissure and some sulci are shown on surface of naked spinal cord:of naked spinal cord:前正中裂前正中裂 Anterior median fissureAnterior median fissure on m