mbbs6yr sys ana note20-spinal cord

1、Copy Right- Hongqi ZHANG-Department of Anatomy-Fudan UniversitySystematicAnatomyDepartment of Anatomy,Histology & Embryology Shanghai Medical College,Fudan UniversityDr.Hongqi Zhang (張)Email:Office:Building 9,Room308，542371519308 Mobileopy Right- Hongqi ZHANG-Depart

2、ment of Anatomy-Fudan University1Copy Right- Hongqi ZHANG-Department of Anatomy-Fudan UniversitySpinal cordCopy Right- Hongqi ZHANG-Department of Anatomy-Fudan UniversityCentral nervous system (CNS)u BrainTelencephalonDiencephalonCerebellumBratem1-Midbrain 2-Pons3-medulla oblongatau Spinal cordPosit

3、ion of the Spinal Cordu Position: Lies in vertebral canal, 45cm long approximatelyu Upper end: Continuous with medulla oblongata at foramen magnumu Lower end: at the lower border of L1 in adult at newborn at level of L3u Sexual difference: usually a little lower in female than in maleu Clinic signif

4、icance: anaesthesia done usually at below the L1py Right- Hongqi ZHANG-Department of Anatomy-Fudan UniversityCoAnaesthesia in the vertebral canalutaneous fascia Supraspinal lig.L1Interspinal lig.Yellow lig.Lower end Of spinal cordNeedle punctureDraw cerebrospinal fluid From the vertebral canal For l

5、ab examinationCopy Right- Hongqi ZHANG-Department of Anatomy-Fudan University External Features of Spinal Cordu External feature:A long cylindrical structure & slightly flattened anteroposteriorlyu Two enlargementsCervical enlargementcorresponds to C4 -T1 of spinal cord Lumbosacral enlargement corre

6、sponds to L2 to S3 of spinal cordu Filum terminale-only thin filamentu Conus medullarisu Cauda equinaLumbosacralenlargementConus medullarisFilum terminaleCauda equinaConus medullaris and cauda equina External Features of Spinal CordFissure and sulciu 1 - Anterior median fissureu 2 - Posterior median

7、 sulcusu 3 - Anterolateral sulcus - connect with ant.root (motor)u 4 - Posterolateral sulcus - connect with post.root (sense)24Post.rootSpinal ganglionPost.branchAnt.root13Ant.branch Segments of Spinal Cordu A portion of the cord that gives rise to a pair of spinal nerve constitutes a segment.u Ther

8、e are 31 segments 8 cervical ss12 thoracic ss5 lumbar ss5 sacral ss1 coccygeal s Segment - sCopy Right- Hongqi ZHANG-Department of Anatomy-Fudan University Relationship of SC Segments to Vertebral bodyu In the third month of fetal life, the spinal cord occupies the entire length of the vertebral can

9、al.u After that time,there are some difference between spinal cord &vertebral canal in growth speed,that is, the vertebral canal grow faster than that of spinal cord,Spinal cord Vertebralcanal Sc length = vertebral canalAt 3rd fetal monthCopy Right- Hongqi ZHANG-Department of Anatomy-Fudan Universit

10、yRelationship of SC Segments to VertebraeCopy Right- Hongqi ZHANG-Department of Anatomy-Fudan UniversityAt birthThe inferior ends is below at the lower border of L1 in adult;at birth at level of L3, usually a little lower in female than in male.But each spinal nerveL3have to come out from theircorre

11、sponding intervertebral foramina.Sc inf. end is At the level of L 1 at adultSc inf. end is higher Than that of canalG-Department ofy-FudanCopy Right- Hongqi ZHANAfter 3rd monthAnatom At birthUniversityopy Right- Hongqi ZHANG-Department of Anatomy-FuCopy Right- Hongqi ZHANG-Department of Anatomy-FCda

12、n UniversityMore high levelMore almost horizental. More lower levelMore obliquityudan University Relationship of SC Segments to Vertebral NumbersSpinal segmentsVertebral levels (spines)Upper cervical region (C1C4)Lie opposite the corresponding vertebraeLower cervical and upper thoracic region (C58；T

13、1-4)One lower in number than corresponding vertebraeMiddle thoracic region (T5T8)Two lower in number than corresponding vertebraeLower thoracic region (T9T12)Three lower in number than corresponding vertebraeLumber segmentsT10T12Sacral and coccygeal segmentsL1 Relationship of SC Segments to Vertebra

14、l NumbersSpinal segmentsVertebral levels (spines)Upper cervical region (C1C4)= C1 C4Lower cervical and upper thoracic region (C5-8；T14)1 = C4 T3Middle thoracic region (T5T8)2 = T3 T6Lower thoracic region (T9T12)3 = T6 T9Lumber segments= T10 T12Sacral and coccygeal segments= L1 Internal structure of

15、spinal cordTLSu 1 - Gray matterCu2 - White matteru 3 reticular formation123C-cervical;T-tharacic;L-lumbar;S-sacralCentral canalInternal structure of spinal cordLat. spinothalamic tractFasciculus gracilis Fasciculus cuneatusLat.corticospinal tractNucleus propriusGray matterMotor neuron of ant.hornWhi

16、te matter Spinal pia matar Spinal arachnoidSpinal dura matar. Post.rootSpinal ganglionSpinal n. Ant.rootght- Hongqi ZHANG-Department of Anatomy-FuCopy RiGray matter of Spinal Corddan UniversityLike a butterfly or letter “H”Consist of cell body,neuroglia and dendrite Located around the central canalP

17、ost. horn (column) Intermediate zonePost. gray commissures Ant. gray commissuresAnt. horn (column)Copy Right- Hongqi ZHANG-Department of Anatomy-Fudan University Gray Matter of Spinal Cordu Anterior horn (column)u Posterior horn (column) Lateral horn (column)is present in the thoracic& upper lumber

18、segments of the cord (T1-L3) onlyu Intermediate zoneu Ant. gray commissuresu Post. gray commissures Gray Matter of Spinal CordPosterior horn (column):u 1- Marginal layeru 2- Substantia gelatinosaSituated at the apex of posterior horn throughout the length of spinal cord. Receives fibers are associat

19、ed with the senses cord.u 3- Nucleus proprius1Situated anterior to the substantia gelatinosa throughout the length of spinal cord. Concerns the sensations of pain and temperature23- Hongqi ZHANG-Department of Anatomy-Fudan UGray Matter of Spinal CordCopy RightniversityPosterior horn (column):u Nucle

20、us thoracicus (lable A)Situated at the base of posterior horn and extending from segments C8L3. Associated with proprioceptive endingsACopy Right- Hongqi ZHANG-Department of Anatomy-Fudan UniversityIntermediate zoneu Intermediolateral nucleus (labeled 1)Extends from segments T1L3,Containing sympathe

21、tic preganglionic neuronsu Sacral parasympathetic nucleus : Extends from segments S2S4, Containing parasympathetic preganglionic neuronsu Intermediomedial nucleus (labled A): Throughout the whole length of spinal cord.Associated with receiving viscera afferent information1Copy Right- Hongqi ZHANG-De

22、partment of Anatomy-Fudan UniversityAnterior horn (column):u Two groups of nuclei1-Medial nuclear group: present in most segments of spinal cord, innervating axial (trunk) muscles122-Lateral nuclear group: present only in cervical and lumbosacral enlargements, innervating limb skeletal musclesCopy R

23、ight- Hongqi ZHANG-Department of Anatomy-Fudan UniversityAnterior horn (column): labeled with red coloru three kinds of neurons (motor neuron 2)u - motor neuron: large multipolar neuron, innervates skeletal muscles, producing contraction of musclesu - motor neuron: smaller multipolar neuron, innerva

24、tes intrafusal muscle fibers of neuromuscular spindles, regulating muscular tonusu Interneuron Renshaws cell: negative feedback Rexeds laminau Posterior horn is formed by lamina to ；u Intermediate zone is corresponding to lamina ；u Anterior horn is composed laminae and ；u lamina is the gray matter a

25、round the central canal.Copy Right- Hongqi ZHANG-Department of Anatomy-Fudan Universitylaminaenuclei Posterior marginal nucleus Substantia gelatinosa Nucleus proprius Reticular nucleus Base of posterior column Thoracic nucleus Intermediomedial mucleus Intermediolateral nucleus Sacral parasympathetic

26、 nucleus Medial motor neuron columnLateral motor neuron column gray matter around central canal Important Subdivision of Spinal Cord Gray MatterCopy Right- Hongqi ZHANG-Department of Anatomy-Fudan UniversityHongqi ZHANG-Department of Anatomy-Fudan UniversitWhite matter of spinal cordCopy Right-Organ

27、izationNerve fiber (tract) Around the grey matter Three partsAnt. Funiculus (A.F) Lat. Funiculus (L.F)Ascending & descending fiber Post. Funiculus (P.F) Ascending fiber only White commissure Amissure of WM Pmissure of wmyP.FL.FA.Fpy Right- Hongqi ZCo WM-white matter HANG-Department of A

28、natomy-Fudan University White Matter of Spinal CordWhite matter conta three kinds of fibers: ascending, descending and fasciculus propriusPost. funiculusPost. white commissureLat. funiculusAnt. funiculusAnt. white commissureight- Hongqi ZHANG-Department of Anatomy-Fudan UniCopy RversityWhite matter

29、of spinal cordFiber tract:in CNS, fiber bundle which has similar origin, terminal, course and function.Ascending tract:to conduct the sensory impulse from the trunk and limbs to the brain.Descending tract.to convey the motor information from central nervous system to the trunk and limbs.Copy Right-

30、Hongqi ZHANG-Department of Anatomy-Fudan Universityight- Hongqi ZHANG-Department of Anatomy-Fudan UniCopy RWhite matter of spinal cordNomenclature :Course: pyramid tractOrigin and terminal : Corticospinal tract.Spinothalamic tractversityAppearance of the tract: Fasciculus gracilis General: lateral c

31、orticospinal tract.Fasciculus proprius: both origin & termination of the fascisulus are in the spinal cord.with two direction (ascending & descending), the function take part in different segment reflex.Copy Right- Hongqi ZHANG-Department of Anatomy-Fudan University Major Ascending or sensory Tracts

32、Fasciculus gracilisFasciculus cuneatus Pos. spinocerebellar tractAnt. spinocerebellar tractSpinothalamic tractLat.Spinothalamic tract(rough tonch) Ant.Spinothalamic tract(pain,temperature,sensation)Red color means importantFasciculus cuneatusFasciculus gracilisFasciculus gracilis and fasciculus cune

33、atusFrom pain and temperature And some touch receptorsSpinothalamic tractLateral and anterior spinothalamic tract Summary-ascending tractsTractSite of originFuniculu sTerminationFunctionFasciculus gracilisSpinal ganglia below segment T5PosteriorGracile nucleusConscious proprioceptive (vibratory sens

34、e, and muscle joint sense) and fine touch sensation of trunk and limbsFasciculus cuneatusSpinal ganglia above segment T4Cuneate nucleusPosterior spinocerebellar tractHomolateral nucleus thoracicusLateralCerebellumUnconscious proprioception from limbs and trunkAnterior spinocerebellar tractContralate

35、ral Laminae Lateral Spinothalamic tractLaminae, LateralDorsal thalamusPain, temperature and crude touch sensation of trunk and limbsanterior Spinothalamic tractanterior Descending TractsFasciculus propriusLateral corticospinal tractRubrospinal tractMedial longitudinal fasciculusReticulospinal tractV

36、estibulospinal tract Tectospinal tractAnterior corticospinal tractRed color means important contentLateral and anterior corticospinal tractCoranal section of cerebrumhorizental section of cerebrum horizental section of midbrainhorizental section of ponsLateral corticospinal tractAnterior corticospin

37、al tracthorizental section of medulla ablongatahorizental section of spinal cord Summary - descending tractsTractSite of originFuniculusTerminationFunctionLateralCerebral cortexLateralLaminae ()Voluntary movementcorticospinalanterior horn Motor neurons & interneuronsof skeletal muscle of trunk and l

38、imbsAnterior corticospinalCerebral cortexAnteriorRubrospinalRed nucleusLateralLaminae ()Facilitates activity of flexoranterior horn Motor neurons & interneuron (for flexor)musclesVestibulospinalHomolateralAnteriorLaminae ()Facilitates activity ofvestibular nucleianterior horn Motor neurons & interne

39、uron (for extensor)extensor musclesReticulospinalReticular formationAnterior & lateralLaminae ()Control Voluntary movement of skeletal muscle of trunk & proximal extremity Summary - descending tractsTractSite of originFuniculusTerminationFunctionMedial longitudinal fasciculusVestibular nucleiAnterio

40、rLaminae (） Anterior horn cellCoordinate of head and eye movementTectospinalSuperior colliculusAnteriorLaminae（） Reflex head turningFasciculus propriusSpinal cordAnterior, lateral & posteriorSpinal cordIntr ic reflex mechanism of spinal cord Main functions of spinal cordu Conduction of excitations b

41、ridge; brain - periphery Sensory impulse to brain Motor impulse to peripheryu ReflexSomatic reflex (skeletal m contration) superficial and deep reflexTendon (stretch reflex ) arc Flexor reflexAbdominal reflexVisceral reflex (sm,cardiac m,gland) Defecation reflexCarotid reflexCopy Right- Hongqi ZHANG

42、-Department of Anatomy-Fudan UniversitySpinal cord transverse section lesionComplete spinal cord transection results in the immediate Loss of all neural function below the level of the lesion.there is a complete lose below the level of the lesion of :All somatic sensation All motor functionAll visce

43、ral sensation All reflex activityAll muscle tone,etcSpinal shock: last for 16 weeksCopy Right- Hongqi ZHANG-Department of Anatomy-FudanUniversityCopy Right- Hongqi ZHANG-Department of Anatomy-Fudan University Hemisection of the spinal cord (brown-sequard syndrome)sensation2133motor45Injured maensory

44、 fasiculus： 1- Fasciculus gracilis2- Fasciculus cuneatus 3-Spinothalamic tractInjured motor fasiculus： 4 - Lat.corticospinal tract 5 - Ant.corticospinal tractCopy RigRight:deep sensation,limb paralysisht- Hongqi ZHANG-Department of AnaLeft :superficial sensation disfunction tomy-Fudan Universityy Ri

45、ght- Hongqi ZHANG-Department of Anatomy-Fudan UniCopersityvHemisection of the spinal cord Brown-sequard syndromeResult in:u The ipsilateral motor neuron paralysis below the level of lesion Resulted from damage to the ipsilateral corticospinal tract.u Loss of the ipsilateral deep sensation (proprioce

46、ptive,vibratroy and twopoint discrimination sense)below the level of lesion . resulted from damage to the fasciculus gracilis and fasciculus cuneatus.u Loss of the contralateral superficial sensation (pain & thermal Sense)below the level of lesion. resulted from damage to the lateral spinothalamic t

47、ract.Copy Right- Hongqi ZHANG-Department of Anatomy-Fudan UniversityCopy Right- Hongqi ZHANG-Department of Anatomy-Fudan UniversityLesion of anterior horn of the spinal cordIt causes ipsilateral lower motor neuron paralysis in the segments of the lesion (resulting from damage to lower motor neurons)such as infantile paralysis (Poliomyelitis).Usually it is caused by poliomyelitis virusMotor neuronCopy Right- Hongqi ZHANG-Department of Anatomy-Fudan UniversityCopy Right- Hongqi ZHA