第三節(jié)神經(jīng)系統(tǒng)的傳導(dǎo)通路

1、The Motor Pathways 運(yùn) 動 傳 導(dǎo) 路,（一） Pyramidal System 錐體系,The motor pathways are concerned with motor function, include pyramidal system 錐體系 extrapyramidal system 錐體外系,It concerned with voluntary moveme

2、nt 隨意運(yùn)動of the skeletal m. and is composed of two orders of neurons: upper motor neuron 上運(yùn)動神經(jīng)元lower motor neuron 下運(yùn)動神經(jīng)元,upper motor neuron,lower motor neuron,effector,,,,,The pyramidal system consists of corticospina

3、 tract 皮質(zhì)脊髓束 corticonuclear tract 皮質(zhì)核束,upper motor neuron,lower motor neuron,effector,Upper Motor Neurons,lie in the motor area of cerebral cortex, Connect directly or through interneurons to lower motor neurons,,Lower

4、 Motor Neurons,include cranial motor nuclei and motor neurons in anterior horn of spinal cord. their axons leave the CNS and extend though peripheral nerves to supply skeletal muscles,,Corticospinal tract,,Corticospin

5、al tract,,Decussation of pyramid,,Lateral corticospinal tract,,Anterior corticospinal tract,,upper motor neuron,upper motor neuron is the Giant pyramidal cells (Betz cells) 巨大錐體細(xì)胞 and other pyramidal cells in superior 2/

6、3 of precentral gyrus and ant. part of paracentral lobule,,1. Corticospinal Tract 皮質(zhì)脊髓束,,,,,,,,Lower motor neuron is the Motor neurons of anterior horn of spinal cord,2.Corticonuclear Tract 皮質(zhì)核束,,,,,,Giant pyramidal

7、cells and other pyramidal cells in lower 1/3 of precentral gyrus,Genu of internal capsuleBrain stem,,Cranial nerves,Bilateral： nucleus of oculomotor n., nucleus trochlear n., motor nucleus of trigeminal n.,

8、 nucleus of abducent n. ambiguus nucleus, nucleus of accessory n. superior part of facial nucleus.,,,,,,,,,,,The Corticonuclear tract send out fibers to end,Contralateral: inferior part of facial nucleus 面神經(jīng)核下

9、半hypoglossal nucleus 舌下神經(jīng)核.,,,,,,,,,,,,,,Corticonuclear tract,,hypoglossal nucleus and inferior part of facial nucleus receive only the fibers from the contralateral corticonucleal tract.,facial nucleus,hypoglossal

10、nucleus,,The injury of the unilateral corticonuclear tract can usually cause the paralysis of the contralateral glossal m. and facial m. below the palpebral fissure. The paralysis caused by the injury of the upper m

11、otor neuron is called supranuclear paralysis 核上癱; The paralysis caused by the injury of the lower motor neuron is called the infranuclear paralysis 核下癱,,infranuclear paralysis of facial n. 面神經(jīng)核下癱,supranuclear p

12、aralysis of facial n. 面神經(jīng)核上癱 ---- the paralysis of facial m. in opposite side below the pelpebral fissure 對側(cè)瞼裂以下面肌癱瘓,---- the paralysis of facial m. of same side 同側(cè)面肌癱,,supranuclear paralysis of hypoglossal n.舌下神

13、經(jīng)核上癱 ----when tongue extend, the apex of tongue inclined to the opposite side,Effects of Upper and Lower Motor Neuron Damage,（二） Extrapyramidal System 錐體外系,composision：the extrapyramidal System include the following

14、structures,Cerebral cortex、corpus striatum 紋狀體、dorsal thalamus、subthalamus、red necleus、substantia nigra、pontine neuclei腦橋核、vestibular neuclei、cerebelum、reticular formation and the fibers connection among them.,（二） Extrap

15、yramidal System 錐體外系,2. character,,,,,新紋狀體—黑質(zhì)環(huán)路,,,,皮質(zhì)—新紋狀體—丘腦—皮質(zhì)環(huán)路,1、The cortico-neosstriated body-dorsothalamus –cortex circuit,2、The neostriated body-subsantia nigra circuit,對皮質(zhì)運(yùn)動區(qū)有反饋調(diào)節(jié)作用,多巴胺能通路，損傷可致震顫麻痹,,,,,,皮質(zhì)- 腦橋 -

16、小腦 - 皮質(zhì)環(huán)路,3、the corticoponto-cerebellar-cortex circuit,協(xié)調(diào)隨意運(yùn)動，損傷表現(xiàn)共濟(jì)失調(diào),4. 錐體系損傷及表現(xiàn)：,①脊髓前角及脊神經(jīng)損傷：,軟癱 flaccid paralysis,②脊髓外側(cè)索損傷：,同側(cè)損傷平面以下硬癱 hard paralysis,③延髓錐體交叉以上處損傷：,對側(cè)上、下肢硬癱,,,,,,,,如內(nèi)囊損傷,,,,1. Injury of the internal c

17、apsule,,1. Injury of the spinal cord,3. Upper、Lower Motor Neurons 上、下運(yùn)動神經(jīng)元,① Upper motor Neurons:,指大腦皮質(zhì)的錐體細(xì)胞及其軸突,② Lower motor Neurons:,指脊髓前角細(xì)胞和腦神經(jīng)運(yùn)動核細(xì)胞,③上運(yùn)動神經(jīng)元損傷（核上癱 supranuclear paralysis)：在皮質(zhì)脊髓束表現(xiàn)為硬癱(hard paralysis),

18、即,肌張力(tonicity of muscles)增高、肌肉不萎縮(without atrophy)、深反射亢進(jìn)、出現(xiàn)病理反射等；在皮質(zhì)核束表現(xiàn)為：即對側(cè)眼裂以下的面肌癱瘓和舌肌癱瘓（伸舌時舌尖偏向?qū)?cè)）。,④下運(yùn)動神經(jīng)元損傷（核下癱 infranuclear paralysis)：在皮質(zhì)脊髓束表現(xiàn)為 軟癱 ( flaccid paralysis or soft paralysis).，,即肌張力降低、肌肉萎縮(muscles at