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1、The Motor Pathways 运 动 传 导 路（一） Pyramidal System 锥体系The motor pathways are concerned with motor function, include pyramidal system 锥体系 extrapyramidal system 锥体外系 It concerned with voluntary movement 随意运动of the skeletal m. and is composed of two orders of neurons: upper motor neuron 上运动神经元lower motor
2、 neuron 下运动神经元upper motor neuron lower motor neuroneffectorThe pyramidal system consists of corticospina tract 皮质脊髓束corticonuclear tract 皮质核束upper motor neuron lower motor neuroneffectorUpper Motor NeuronsUpper Motor Neuronslie in the motor area of cerebral cortex,Connect directly or through Connect
3、 directly or through interneuronsinterneurons to to lower motor neuronslower motor neurons, , Lower Motor NeuronsLower Motor Neuronsinclude cranial motor nuclei and motor neurons in anterior horn of spinal cord. their axons leave the CNS and extend their axons leave the CNS and extend though periphe
4、ral nerves to supply skeletal though peripheral nerves to supply skeletal musclesmusclesCorticospinal tractCorticospinal tractDecussation of pyramid Lateral corticospinal tractAnterior corticospinal tract upper motor neuron Lower motor neuronupper motor neuron is the Giant pyramidal cells (Betz cell
5、s) 巨大锥体细胞 and other pyramidal cells in superior 2/3 of precentral gyrus and ant. part of paracentral lobule1. Corticospinal Tract 皮质脊髓束Motor neurons of anterior hornLateral corticospinal tractAnterior corticospinal tractLower motor neuron is the Motor neurons of anterior horn of spinal cord2.Cortico
6、nuclear Tract 皮 质核束Giant pyramidal cells and other pyramidal cells in lower 1/3 of precentral gyrusGenu of internal capsuleBrain stemCranial nervesCranial motor neuclei 脑神经运动核upper motor neuronlower motor neuronSkeletal m. of the head ,neck and face.Corticonuclear TractBilateral： nucleus of oculomot
7、or n., nucleus trochlear n., motor nucleus of trigeminal n., nucleus of abducent n. ambiguus nucleus, nucleus of accessory n. superior part of facial nucleus. The Corticonuclear tract send out fibers to endContralateral:inferior part of facial nucleus 面神经核下半hypoglossal nucleus 舌下神经核. facial nucleush
8、ypoglossal nucleusCorticonuclear tracthypoglossal nucleus and inferior part of facial nucleus receive only the fibers from the contralateral corticonucleal tract. facial nucleushypoglossal nucleusThe injury of the unilateral corticonuclear tract can usually cause the paralysis of the contralateral g
9、lossal m. and facial m. below the palpebral fissure.The paralysis caused by the injury of the upper motor neuron is called supranuclear paralysis 核上瘫; The paralysis caused by the injury of the lower motor neuron is called the infranuclear paralysis 核下瘫 infranuclear paralysis of facial n. 面神经核下瘫 supr
10、anuclear paralysis of facial n. 面神经核上瘫 - the paralysis of facial m. in opposite side below the pelpebral fissure 对侧睑裂以下 面肌瘫痪- the paralysis of facial m. of same side 同侧面肌瘫infranuclear paralysis of hypoglossal n. 舌下神经 核下瘫 -when tongue extend, the apex of tongue inclined to the same sidesupranuclear p
11、aralysis of hypoglossal n.舌下神经核上瘫 -when tongue extend, the apex of tongue inclined to the opposite sideEffects of Upper and Lower Motor Neuron DamageUMN damage ( supranuclear paralysis )LMN damage ( infranuclear paralysis )ParalysisSpastic 痉挛性（硬瘫）Flaccid 软瘫Muscle tone 肌张力 IncreasedDecreasedtendon re
12、flexes 腱反射IncreasedDecreased Pathological reflexes病理反射Positive ()Negatively ()Amyotrophy 肌萎缩No presentDistinctly 明显（二） Extrapyramidal System 锥体外系1. composision：the extrapyramidal System include the following structuresCerebral cortex、corpus striatum 纹状体、dorsal thalamus、subthalamus、red necleus、substa
13、ntia nigra、pontine neuclei脑桥核、vestibular neuclei、cerebelum、reticular formation and the fibers connection among them.（二） Extrapyramidal System 锥体外系2. character发生古老，在鸟类以下是控制运动的中枢。结构复杂、纤维联系广泛，因此是多级神经元的传导通路 在功能上与锥体系是统一的整体，锥体系功能的实现有赖于锥体外系保证稳定的肌张力,而锥体外系功能的实现也需要依赖锥体系的发动。 主要参与调节肌张力、协调肌肉活动、维持体态姿势和习惯性动作。新纹状体黑
14、质环路皮质新纹状体丘脑皮 质环路1、The cortico- neosstriated body- dorsothalamus cortex circuit2、The neostriated body-subsantia nigra circuit对皮质运动区有反馈调节作用多巴胺能通路，损伤可致震颤 麻痹皮质- 脑桥 - 小脑 - 皮质 环路3、the corticoponto- cerebellar-cortex circuit协调随意运动，损伤表现 共济失调4. 锥体系损伤及表现：脊髓前角及脊神经损伤：软瘫 flaccid paralysis 脊髓外侧索损伤：同侧损伤平面以下硬瘫 hard
15、 paralysis延髓锥体交叉以上处损伤：对侧上、下肢硬瘫如内囊损伤1. Injury of the internal capsule1. Injury of the spinal cord3. Upper、Lower Motor Neurons 上、下运动神经元 Upper motor Neurons:指大脑皮质的锥体细胞及其轴突 Lower motor Neurons:指脊髓前角细胞和脑神经运动核细胞上运动神经元损伤（核上瘫 supranuclear paralysis)：在皮质脊髓束 表现为硬瘫(hard paralysis), 即肌张力(tonicity of muscles)增高、肌肉不萎缩(without atrophy)、深反射亢 进、出现病理反射等；在皮质核束表现为：即对侧眼裂以下的面肌瘫痪和 舌肌瘫痪（伸舌时舌尖偏向对侧）。下运动神经元损伤（核下瘫 infranuclear paralysis)：在皮质脊髓束 表现为 软瘫 ( flaccid paralysis or soft paralysis).，即肌张力降低、肌肉萎缩(muscles atrophy) 、深、浅反射消失、无病 理反射等；在皮质核束表现为：即同侧全部面肌瘫痪和舌肌瘫痪（伸舌 时舌尖偏向同侧）。
