神經(jīng)系統(tǒng)對運動的調(diào)節(jié)

1、會計學(xué)1神經(jīng)系統(tǒng)對運動的調(diào)節(jié)神經(jīng)系統(tǒng)對運動的調(diào)節(jié)23The mental body image seems to be generated by somatosensory, proprioceptive, and visual inputs to the posterior parietal cortex (area 5, area 7)4Represented by the association areas of neocortex and basal ganglia of the forebrainIs concerned with : The goal of the movement

2、 and the movement strategy that best achieves the goal5tacticsRepresented by the motor cortex and cerebellumIs concerned with tactics The sequences of muscle contractions Arranged in space and timeRequired to smoothly and accurately achieve the strategic goal6execution Represented by the brain stem

3、and spinal cord Is concerned with execution Action of the motor neuron and interneuron pools that generate the goal-directed movement and make any necessary adjustments of posture789SensorimotorcortexBasalgangliaCerebellumBrain stemSpinal cordInterneuron - MotorneuronMotor unit(final common pathway)

4、Receptorsmuscle, skin, joint12345vThese programs are accessed, executed, and modified by descending commands from the brainThe brains command and control of the motor programs in the spinal cordvThe motor system consists of all our muscles and the neurons that command themvThe spinal cord contains c

5、ertain motor programs for the generation of coordinated movements vThe motor control can be divided into two parts:The spinal cords command and control of coordinated muscle contraction1011 vThe rhythmic movements could be elicited in the hind legs of cats and dogs long after their spinal cords had

6、been severed from the rest of the central nervous systemCharles Sherington & Graham Brown (English) The importance of circuitry within the spinal cord for the coordinated control of movements1213nAlpha motor neurons Innervate skeletal muscle (extrafusal muscle) Function: directly command muscle

7、contractnGamma motor neurons Innervate muscle spindle (intrafusal muscle) Function: regulating the muscle spindlenInterneurons Allows coordinated motor programs to be generatedFinal common pathway (directly command muscle contract)1415The motor unit is an alpha motor neuron and all of the muscleThe

8、motor neuron pool is all of the alpha motor neurons that innervate one muscle1630 mixed spinal nervescervical 1-8thoracic 1-12lumbar 1-5sacral 1-5The ventral horn of the spinal cord contains motor neurons that innervate skeletal muscle fibersVentral roots + Dorsal root = Spinal nerve17The cervical e

9、nlargement of the spinal cord contains the motor neurons that innervate the arm musclesThe lumbar enlargement contains neurons that innervate the muscles of the leg支配上肢的神經(jīng)元集群位于頸膨大處，支配下肢的則在腰膨大處支配上肢的神經(jīng)元集群位于頸膨大處，支配下肢的則在腰膨大處The distribution of motor neurons in the spinal cordThe motor neurons that inner

10、vate distal and proximal musculature are found mainly in the cervical and lumbar-sacral segments of the spinal cordWhereas those innervating axial musculature are found at all levelsSegments C3-T1 have a swollen ventral horn that innervate skeletal musculature in armsSegments L1-S3 have a swollen ve

11、ntral horn that innervate skeletal musculature in legs18Motor neurons controlling flexors lie dorsal to those controlling extensors Motor neurons controlling axial muscles lie medial to those controlling distal muscles支配軀干部肌肉的神經(jīng)元位于脊髓前角灰質(zhì)最內(nèi)側(cè)，由此向外排列的神經(jīng)元則支配肢體由近及遠(yuǎn)分布的肌肉The distribution of lower motor neu

12、rons in the ventral horn19下運動神經(jīng)元的損傷表現(xiàn)20Lou Gehrig Farewell Speech:Fans, for the past two weeks you have been reading about the bad break I got. Yet today I consider myself the luckiest man on the face of this earth. So I close in saying that I may have had a tough break, but I have an awful lot to l

13、ive for.Lou Gehring, a star baseball player with New York Yankees, who died of ALS ( amyotrophic lateral sclerosis) in 193621This input is important for the initiation and control of voluntary movementThis input may be excitatory or inhibitory and is part of the circuitry that generates the spinal m

14、otor programsThis input provides feedback about muscle length2223ReceptorEffectorSpinal Motor Neuron(center)SkinMuscleJointMuscle contractionHigherCenterVoluntary movementsNociceptive stimulusStretch musclesPosture maintenance24vTwo types of myotatic reflex Tendon reflex and muscle tonusA.Tendon ref

15、lex 快速牽拉肌腱而發(fā)生的牽張反射Clinic application：了解脊髓不同節(jié)段的功能狀態(tài) 肘反射扣擊肱二頭肌肌腱頸5-7肘部屈曲膝反射扣擊股四頭肌肌腱腰2-4小腿伸直跟腱反射扣擊跟腱腰5-骶2腳向足底方向屈曲單突觸反射潛伏期很短，約0.7s 只夠一次突觸傳遞時間延擱2526B. Muscle tonus 肌肉受到緩慢而持續(xù)的牽拉而發(fā)生的收縮 使骨骼肌能保持一定的肌肉張力 意義: 維持身體的姿勢(posture)，而不表現(xiàn)明顯的動作 表現(xiàn)：extensor(伸肌)和flexor(屈肌)都發(fā)生肌緊張直立時，以伸肌緊張為主，因重力作用于關(guān)節(jié)，使關(guān)節(jié)趨向彎曲， 伸肌受到牽拉，引起肌緊張反射

16、，肌緊張度增加以對抗關(guān)節(jié)屈曲 因重力持續(xù)作用于關(guān)節(jié)，肌緊張也就持續(xù)發(fā)生。使直立姿勢得以維持多突觸反射潛伏期較長，經(jīng)過多個突觸傳遞27 Muscle spindles:nConsists of specialized skeletal muscle fibersnIn this middle region, group Ia sensory axons wrap around the muscle fibers of the spindlenThe spindles and their associated Ia axons, specialized for the detection of c

17、hanges in muscle length (stretch): proprioceptors and propriceptionnIa axons are the thickest myelinated axons so they conduct action potentials very rapidlynIa axons enter the spinal cord via the dorsal roots, branch repeatedly, and form excitatory synapses upon both interneurons and alpha motor ne

18、urons of the ventral hornsvMuscle spindle 是一種可感受肌肉長度變化或感受牽拉刺激的 本體感受器v梭內(nèi)肌感受部裝置位于中間,收縮成分位于兩端, 梭內(nèi)肌收縮時或牽拉梭外肌時, 感受裝置對牽拉敏感性增高 28+29nExtrafusal fibers are innervated by alpha motor neuronsnIntrafusal fibers receive their motor innervation by another type of lower motor neuron called a gamma motor neuronnGa

19、mma motor neurons innervate the intrafusal muscle fiber at the two ends of the muscle spindle nActivation of these fibers causes a contraction of the two poles of the muscle spindle, thereby pulling on the non-contractile equatorial region and keeping the Ia afferents active30Activation of alpha mot

20、or neurons shortens the extrafusal muscle fibers. If the muscle spindle becomes slack, it goes “off the air” and no longer reports the length of the muscleActivation of gamma motor neurons contracts the poles of the spindle, keeping it “on the air”3132vGolgi tendon organnActs like a strain gauge, it

21、 monitors muscle tension, or the force of contractionnLocated at the junction of the muscle and the tendon and are innervated by group Ib sensory axons that are slightly smaller than the Ia axons innervating the muscle spindles33Golgi tendon organs respond to increased tension on the muscle and tran

22、smit this information to the spinal cord via type Ib sensory afferents. Because the activated muscle does not change length, the Ia afferents remain silent in this example當(dāng)肌肉等長收縮時,腱器官傳入沖動頻率, 肌梭傳入沖動頻率不變;當(dāng)肌肉等張收縮時,腱器官傳入沖動頻率不變, 肌梭傳入沖動頻率Golgi tendon organs lie in series between the muscle fibers and thei

23、r points of attachmentMuscle spindles are arranged parallel to the extrafusal fibers34The Ib afferents enter the spinal cord, branch repeatedly, and synapse on interneurons in the ventral hornSome of these interneurons form inhibitory connections with the alpha motor neurons innervating the same mus

24、cle. This is the basis for the reverse myotatic reflex-Muscle spindle situated in parallel with the muscle fibers, Golgi tendon organs are situated in seriesIa activity from the spindle encodes muscle length informationWhile Ib activity from the Golgi tendon organ encodes muscle tension information腱

25、器官 是張力感受器, 其傳入沖動對同一肌肉運動神經(jīng)元起抑制作用肌梭是長度感受器,其傳入沖動對同一肌肉運動神經(jīng)元起興奮作用當(dāng)肌肉被動牽拉時, 二者傳入沖動頻率均：首先興奮肌梭發(fā)動牽張反射, 肌肉收縮,牽拉力大到一定程度, 興奮腱器官而抑制牽張反射牽張反射的特點： 反射弧簡單，感受器和效應(yīng)器在同一塊肌肉353637nInhibitory inputnContraction of one set of muscles accompanied by the relaxation of the antagonist muscles is called reciprocal inhibitionnReci

26、procal inhibition is also used by descending pathways to overcome the powerful myotatic reflex38(A & C fibers)nExcitatory inputnFlexor reflex: used to withdraw a limb from an aversive stimulus, such as the withdrawal of your foot from the thumbtacknThe pain fibers entering the spinal cord branch

27、 profusedly and activate interneurons in several spinal segments. These cells eventually excite the alpha motor neurons that control all of the flexor muscles of the affected limb (and inhibitory interneurons are also recruited to inhibit the alphas that control the extensors)+39SpinalcordIpsilatera

28、lextensorsinhibitedContralateralextensorsactivated(contract)Ipsilateralflexorsactivated(contract)ContralateralflexorsinhibitedIpsilateralknee jointcloses up to remove footfrom tackContralateralknee jointopens up to support greaterweight40414243Some neurons respond to the activation of NMDA receptors

29、 with rhythmic depolarization(a) In the resting state, the NMDA receptor channels and the calcium-activated potassium channels are closed(b) Glutamate causes the NMDA receptors to open, the cell membrane to depolarize, and Ca2+ ions to enter the cell(c) The rise in intracellular Ca2+ causes the Ca2+

30、-activated potassium channels to open. K+ ions leave the neuron, hyperpolarizing the membrane. The hyperpolarization allows Mg2+ ions to enter and clog the NMDA channel, arresting the flow of Ca2+(d) As Ca2+ falls, the potassium channels close, resetting the membrane for another oscillation44Walking

31、 is initiated when a steady input excites two interneurons that connect to the motor neurons controlling the flexors and extensors, respectively. The interneurons respond to a continuous input by generating bursts of outputs. The activities of the two interneurons alternate because they inhibit each

32、 other via other (inhibitory) interneurons. Thus, a burst of activity in one interneuron strongly inhibits the other(Pacemaker neuron)(Pacemaker neuron)4546474849Control posture and under brain stem controlContol voluntary movements of the distal musculature and under direct cortical control50(Pyram

33、idal tract)Control fine movements of the arms and fingersThe effects of lateral pathway lesions(in monkeys)by Donald Lawrence & Hans Kuypers (in the late 1960s)Join in corticospinal tract in the lateral column of the spinal cordTerminate in the dorsolateral region of the ventral horns and interm

34、edial gray matterWhere motor neurons and interneurons control the distal muscles, particularly flexorsInput from frontal cortex51nContain four descending tracts the vestibulospinal tractthe tectospinal tractthe pontine reticulospinal tractthe medullary reticulospinal tractn Oringinate in the brain s

35、tem n Terminate among the spinal interneuronsn Controlling proximal and axial musclesnUse sensory information about balance, body position, and the visual enviroment to reflexively maintain balance and body posture52The vestibulospinal and tectospinal tracts keep the head balance on the shoulders as

36、 the body moves through space , and they turn the head in response to new sensory stimuli(midbrain)Recive direct input from retinaRecive projections from visual cortex, as well as afferents carring somatosensory and auditory informationConstruct a map of the word around usThe motion of the fluid in

37、this labyrinth, which accompanies movements of the head, activates hair cells that signal the vestibular nuclei via cranial nerve VIIIOne: Projects bilaterally down the spinal cord and activates the cervical spinal circuits that control neck and back muscles and guid head movementRely sensory inform

38、ation from the vestibular labyrinth in the inner earAnother: Projects ipsilaterally as far down as the lumbar spinal cordIt helps us maintain an upright and balanced posture by facilitating extensor motor neurons of the legsStimulation at one site in this map Lead to an orienting response that direc

39、ts the head and eyes to move53The pontine reticulospinal tract enhance the antigravity reflexes of the spinal cordBy facilitating the extensors of the lower limbsHelps maintain a standing posture by resisting the effects of gravityThe medullary reticulospinal tract has the opposite effect: it libera

40、tes the antigravity muscles from reflex controlActivity in both reticulospinal tracts is controlled by descending signals from the cortexControl posture of the trunk and the antigravity muscles of the limbs545556(Primary motor cortex)(Premotor area) (lateral region)(Supplementary motor area) (medial

41、 region)Areas of neocortex intimately involved in the planning and instruction of voluntary movementThe motor cortex is a circuscribed region of the frontal lobeArea 4 lies just anterior to the central sulcus on the precentral gyrusArea 6 lies just anterior to area 45758運動皮層對軀體運動的調(diào)控特點：交叉性：但頭面部肌肉的支配是

42、雙側(cè)性的有精細(xì)的功能定位：大體呈身體倒影:在4區(qū)內(nèi)側(cè)近中線部位是下肢代表區(qū)，向外側(cè)依次為軀干、前臂、手指，最外側(cè)靠近外側(cè)溝處為面部和舌代表區(qū)頭面代表區(qū)內(nèi)部為正立的運動精細(xì)部位其代表區(qū)大：如手指和面部59Prefrontal areas: in humans are thought to be important for abstract thought, decision making, and anticipating the consequences of actionnArea 6 and 4 together contribute most of the axons to the de

43、scending corticospinal tractnArea 6 lies at the junction where signals encoding what actions are desired are converted into signals that specify how the action will be carried outPrefrontal areas, along with the posterior parietal cortex , represent the highest levels of the motor control hierarchy,

44、 where decisions are made about what actions to take and their likely outcomenBoth the prefrontal and the parietal cortex send axons that converge on cortical area 6Area 5, receives inputs from primary somatosensory cortical area 3,1,2Area 7, receives inputs from higher-order visual cortical areas (

45、MT)The contributions of posterior parietal and prefrontal cortexFor abstract thought, decision making, and anticipating the consequences of action60Pyramidal cellIn cortical layer V(Motor cortex,M1,Area 4)Area 6(anterior)Area 3,1,2(posterior)Lower motor neurons of spinal cordThalamus(VLc)CerebellumB

46、rain stemBasal gangliaThalamus(VLo)Somatosensory inputs61nUsing PET (positron emission tomography) to monitor changes in the patterns of cortical activation that accompany voluntary movementsnWhen the subjects were asked to perform a series of finger movements from memory, the following regions of c

47、ortex showed increased blood flow: the somatosensory and posterior parietal areas, parts of the prefrontal cortex (area 8), area 6, and area 4nPlay a role in generating the intention to move and converting that intention into a plan of actionnWhen the subjects were asked only to rehearse the movemen

48、t mentally without actually moving the finger, area 6 remained active but area 4 did notPer Roland and his colleagues (Danish neurologist)62The discharge of a cell in the premotor area (PMA) before a movementArea 6 (SMA and PMA) plays an important role in the planning of movement, particularly compl

49、ex movement sequences of the distal musculature(a) Ready: A monkey sits before a panel of lights. The task is to wait for an instruction stimulus that will inform him o the movement required to receive a juice reward, then perform the movement when a trigger stimulus goes on. The activity of a neuro

50、n in PMA is recorded during the task(b) Set: the instruction stimulus occurs at the time indicated by the upward arrow, resulting in the discharge of the neuron in PMA(c) Go: shortly after the movement is initiated, the PMA cell ceases firing636465666768697071727374基底神經(jīng)節(jié)(basal ganglia)是從端腦衍生的一些皮層下神經(jīng)

51、核團(tuán)的總稱，位于大腦兩半球的深部?；咨窠?jīng)節(jié)中與運動功能有關(guān)的主要是紋狀體(striatum)尾核與殼核是基底神經(jīng)節(jié)的主要輸入核(input nuclei)，蒼白球的內(nèi)側(cè)部、腳內(nèi)核和黑質(zhì)網(wǎng)狀部是基底神經(jīng)節(jié)的主要輸出核(output nuclei)，后兩者的結(jié)構(gòu)和機(jī)能也很相似75紋狀體的主要傳入沖動來自大腦皮層廣泛的區(qū)域(運動區(qū)、體感區(qū)、聯(lián)合區(qū)、邊緣區(qū)甚至頂葉)傳出沖動經(jīng)過丘腦返回皮層，主要是輔助運動區(qū)(supplementary motor area)和運動前皮層(premotor cortex)，而與脊髓沒有直接的聯(lián)系76n基底神經(jīng)節(jié)與大腦皮層的纖維聯(lián)系，與運動有關(guān)的主要為三條回路1.皮層新

52、紋狀體(尾、殼核)蒼白球(內(nèi)側(cè)部)丘腦皮層2.皮層新紋狀體(尾、殼核) 蒼白球(外)丘腦底核蒼白球(內(nèi))丘腦皮層3.皮層新紋狀體(尾、殼核)黑質(zhì)丘腦皮層771. 皮層皮層 新紋狀體新紋狀體 蒼白球蒼白球( (內(nèi)側(cè)內(nèi)側(cè)) ) 丘腦丘腦 皮層回路皮層回路大腦皮層(包括運動區(qū)、體感區(qū)、聯(lián)合區(qū)、邊緣區(qū)甚至頂葉) 新紋狀體(包括尾核和殼核，即紋狀體的輸入核) 蒼白球的內(nèi)側(cè)部 丘腦(包括腹前核、腹外側(cè)核、內(nèi)側(cè)背核和中央中核) 大腦皮層(主要是運動區(qū)和輔助運動區(qū)皮層)78大腦皮層相當(dāng)廣泛的區(qū)域 新紋狀體 蒼白球的外側(cè)部 丘腦底核 蒼白球的內(nèi)側(cè)部 丘腦 皮層運動區(qū)和運動前區(qū)79大腦皮層相當(dāng)廣泛的區(qū)域(包括運動

53、區(qū)、體感區(qū)、聯(lián)合區(qū)、邊緣區(qū)甚至頂葉) 新紋狀體 黑質(zhì)網(wǎng)狀部 丘腦的腹前核和腹外側(cè)核 大腦皮層(運動區(qū)和輔助運動區(qū))紋狀體(尾殼核)黑質(zhì)間存在具有局部定位特征的往返纖維聯(lián)系從黑質(zhì)的致密部有纖維投向新紋狀體，它組成多巴胺能神經(jīng)元系統(tǒng)；但黑質(zhì)除有纖維至上丘和腳橋被蓋核外，沒有其他向下投射的纖維所以，基底神經(jīng)節(jié)的運動功能是通過大腦皮層中與運動控制有關(guān)的區(qū)域而間接實現(xiàn)的80直接通路易化運動n直接通路包括通路 1 和 3n從皮層到新紋狀體(輸入核)的遞質(zhì)是谷氨酸，是興奮性的；從新紋狀體到蒼白球內(nèi)側(cè)部及黑質(zhì)網(wǎng)狀部(輸出核)的遞質(zhì)是GABA和P物質(zhì)，是抑制性的；從這些輸出核到丘腦的遞質(zhì)也是GABA，也是抑制性

54、的；再由丘腦返回到皮層的輔助運動區(qū)，則是興奮性的。n當(dāng)皮層有興奮沖動下行到紋狀體的輸入核使它興奮時，就會使輸出核中的抑制細(xì)胞抑制，從而激活(去抑制)了丘腦的神經(jīng)元，再通過輔助運動區(qū)和運動前區(qū)激活運動皮層和向腦干及脊髓的投射神經(jīng)元，從而起易化運動的效果81間接通路抑制運動n間接通路包括通路2n從皮層到新紋狀體(輸入核)的遞質(zhì)是谷氨酸，是興奮性的；從紋狀體輸入核到蒼白球外側(cè)部的遞質(zhì)是GABA和腦啡肽，是抑制性的；從蒼白球外側(cè)部到丘腦底核的遞質(zhì)是GABA，也是抑制性的；從丘腦底核到蒼白球內(nèi)側(cè)部(輸出核)的遞質(zhì)是谷氨酸，是興奮性的；從蒼白球內(nèi)側(cè)部到丘腦的遞質(zhì)是GABA，抑制性的；再由丘腦返回到皮層的輔

55、助運動區(qū)，則是興奮性的n當(dāng)皮層與紋狀體輸入核興奮而使蒼白球外側(cè)部抑制時，轉(zhuǎn)而使丘腦底核產(chǎn)生興奮(去抑制)，也就興奮了紋狀體的輸出核，抑制了丘腦，從而降低了輔助運動區(qū)的興奮性，產(chǎn)生抑制運動的效果82黑質(zhì)紋狀體多巴胺能投射易化運動n從黑質(zhì)中的多巴胺能神經(jīng)元發(fā)出纖維到新紋狀體，易化運動n興奮直接通路而易化運動，也就是使新紋狀體通過GABA與P物質(zhì)等抑制紋狀體的輸出核，興奮丘腦，最后起易化運動的作用。n抑制間接通路而易化運動，就是使新紋狀體抑制，致使GABA與腦啡肽的抑制作用降低，因而興奮了蒼白球的外側(cè)部，抑制丘腦底核，從而抑制紋狀體輸出核，興奮了丘腦，最后也起易化運動的作用。所以，多巴胺能投射通過直

56、接通路或間接通路，最后對運動都起易化作用83+-84858687小腦表面存在的大量橫向窄溝，將小腦表面分成許多平行、狹長的葉片(folia)。少數(shù)溝較深，成為裂，將小腦分成若干個小葉(lobule)兩條最深的裂(原裂和后外側(cè)裂)又將小腦橫向地分成三個主要的葉(lobe)前葉、后葉和絨球小結(jié)葉Dorsal viewCross sectionMidsagittal view88小腦由外層的灰質(zhì)(皮層)、內(nèi)部的白質(zhì)和位于白質(zhì)中心的3對小腦深部核團(tuán)(deep cerebellar nuclei)組成，分別是頂核(fastigial nucleus)、間位核(interposed nucleus)和齒狀

57、核(dentate nucleus)。在人類，間位核分化成球狀核和栓狀核89n小腦的傳入聯(lián)系主要來自前庭、脊髓和大腦皮層等處，到達(dá)小腦的傳入纖維分別與小腦深核和小腦皮層的神經(jīng)元形成突觸聯(lián)系n小腦皮層的傳出纖維，即浦肯野細(xì)胞浦肯野細(xì)胞(Purkinje cell)的軸突大多數(shù)投射到小腦深核，再由小腦深核神經(jīng)元發(fā)出離核纖維(nucleofugal fiber)構(gòu)成小腦的傳出，投射到皮層運動區(qū)和腦干的四對運動核團(tuán)(前庭核、網(wǎng)狀結(jié)構(gòu)、上丘、紅核)n所有的小腦傳入和傳出纖維均經(jīng)過三對小腦腳小腦下腳(繩狀體)、小腦中腳(腦橋臂)和小腦上腳(結(jié)合臂)進(jìn)出小腦90內(nèi)側(cè)區(qū)(蚓部)皮層的浦肯野細(xì)胞主要投射到頂核，

58、部分投射到前庭外側(cè)核；中間區(qū)(蚓旁部)和外側(cè)區(qū)的浦肯野細(xì)胞則分別投射到間位核和齒狀核根據(jù)小腦皮層浦肯野細(xì)胞軸突投射到小腦深核，將小腦自內(nèi)側(cè)向外側(cè)，縱向地劃分成三個縱區(qū)內(nèi)側(cè)區(qū)、中間區(qū)和外側(cè)區(qū) 91n內(nèi)側(cè)區(qū)經(jīng)頂核與內(nèi)側(cè)下行系統(tǒng)相連接，控制軀體近端(體軸)肌肉裝置的活動n中間區(qū)經(jīng)間位核連接外側(cè)下行系統(tǒng)，主要調(diào)節(jié)軀體遠(yuǎn)端(肢體)肌肉的活動n外側(cè)區(qū)通過齒狀核與大腦皮層運動區(qū)和運動前區(qū)相聯(lián)系，參與隨意運動的計劃和編程92n從功能和進(jìn)化的觀點來看，可以將小腦劃分成前庭小腦、脊髓小腦和皮層小腦三個主要的功能部分n它們分別主要接受前庭系統(tǒng)、脊髓和大腦皮層的傳入，而且它們的傳出也相應(yīng)地主要作用于前庭核、脊髓和大腦

59、皮層n在脊椎動物的進(jìn)化過程中，這三個功能部分分別隨前庭系統(tǒng)、脊髓和大腦皮層的發(fā)展而先后出現(xiàn)，故又分別被稱為古小腦、舊小腦、和新小腦93n構(gòu)成：主要是絨球小結(jié)葉?？拷q球小結(jié)葉的蚓垂也接受前庭系統(tǒng)的傳入n傳入纖維：初級傳入纖維起自兩側(cè)半規(guī)管和耳石器，次級傳入纖維則是起源于前庭核的間接投射。它們向小腦傳遞了頭部位置變化和頭部相對于重力作用方向的信息n傳出纖維：通過前庭核，經(jīng)前庭脊髓束影響脊髓中支配體軸肌肉的運動神經(jīng)元的興奮性活動，控制體軸肌肉的收縮活動，維持軀體平衡n前庭小腦也接受經(jīng)橋核轉(zhuǎn)接的外側(cè)膝狀體、上丘和紋狀皮層等處的視覺傳入，因而它還通過對眼外肌神經(jīng)核的傳出，控制眼球的運動和協(xié)調(diào)頭部運動時

60、眼球為保持視像而進(jìn)行的凝視運動前庭小腦維持軀體平衡和眼球的運動94n構(gòu)成：脊髓小腦縱貫小腦體的前葉和后葉的正中部分，包括內(nèi)側(cè)區(qū)和中間區(qū)兩個縱區(qū)n傳入：主要來自脊髓的軀體感覺信息，經(jīng)直接的和間接的脊髓小腦通路到達(dá)小腦脊髓小腦還接受經(jīng)腦橋接轉(zhuǎn)的大腦皮層感覺區(qū)和運動區(qū)的傳入信息此外，脊髓小腦還接受視覺、聽覺和前庭信息n傳出：內(nèi)側(cè)區(qū)經(jīng)頂核、中間區(qū)經(jīng)間位核到達(dá)腦干和運動皮層n效應(yīng)：控制腦干和皮層起源的內(nèi)側(cè)和外側(cè)下行系統(tǒng)，對進(jìn)行中的肢體運動起重要的適時調(diào)節(jié)作用脊髓小腦利用感覺反饋信息調(diào)節(jié)肌肉張力和適時地調(diào)節(jié)進(jìn)行中的運動脊髓小腦調(diào)節(jié)肌緊張95n構(gòu)成：皮層小腦即小腦的外側(cè)區(qū)n輸入纖維：來自于大腦皮層的感覺區(qū)、運動區(qū)、運動前區(qū)和感覺