.60.PARTILOCOMOTORSYSTEMcle,belowtohelateralsurfaceandposteriorbordeporal bone above and the head of the mandible below.of the neck of the mandible.The sphenomandibularThe articular surfaces of the joint are covered byligament onthemedialsideofthe jointextendsfromfibrocartilage.The articular capsule is a thin,looseen-thespineofsphenoid bone totheramusofmandibie.velope, attached to the articular circumference of theThe stylomandibular ligament extendsfrom the apextemporal bone above and to the neck of the mandibleand adjacent anterioraspect ofthestyloidprocessofbelow.The joint is reinforced by two ligaments:Thethe temporal bone to the angle and posterior border oflateral ligamentoftemporomandibularjoint,closedtotheramus ofmandible.Itcanonly beconsidered asthe lateral side of the capsule, is attached above to theaccessory to it (Fig.I-2-4).lateral surface of the zygomatic arch and to the tuber-Articular cavityMandibularfossaArticular discLateral ligArticularStyloidprocesscapsuleStylomandibular ligHead ofmandibleFig.I-2-4 The temporomandibular jointThere is an articular disc in the articular cavity,byments are combined in grinding, biting, chewing, andwhich the joint can be divided completely into upperrotation.and lower parts.Thedisc is an oval plate of fibrocarti-The mandible is dislocated only forwards. A ex.lage.Its superiorsurface,toaccommodateitselftothetremely opening ofthe mouth may lead to slipping ofform of mandibular fossa and the articular tubercle,the head of mandible forwards into the infratemporalis sagittally concavo-convex; its inferior surface,infossa. Pulling the mandible down over the articularcontact with the condyle, is concave.tubercle while pushing the jaw backwards may reloThe movements ofthemandiblecan bedepress-cateit.ing or elevating,and protruding or refracting; and aslight amount of side to side movement and rotationSection3.Joints ofare also permitted. These actions involve gliding,Bones of Trunkspin,roll and angulation.Opening and closing of themouth are primarily hinge movements and are con-The vertebral column consists ofthe 24 pieces offined to thelower parts ofthe two joints, when thebae, thesacm andcccy which articulateoemouth is opened more widely,both upper and lowerby one to form a longitudinal axis ofthe trunk.Cranillyparts of the two joints are involved.In protrusion, theitsuporsthskullandlateraygivesaachmenttmovement takes place principally inthe upperpart ofribs.The verebralcolumnreceived the weight ofthethejoint,thedisc and thehead ofmadiblearepulledunk,hd adupper lm,aduallyitsudforward onto the articular tubercle.Inretraction,thewith the hip bones by which the weight of thetrunk.disc and the head of madible are moved backwardheadanduperlimsistranmiedothlowerlimbsintothe mandibularfossa.In lateralmovement oftheThevebralcanalgivessupporstothespinalmandible,thedisc andtheheadofmandiblerotateinosopinalandirrinrone joint andglideforwards intheother.Thesemovelocated within the canal.口扫描全能王创建口
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Chapter 2 Arthrology · 61 .I . Articulations of Verte-.Joints of vertebral bodiesbral ColumnThe adjacent vertebral bodies are mainly jointedby the intervertebral disc and reinforced by the anteri-The vertebrae articulate each other by interverte-orand posterior longitudinal ligaments(Fig.1-2-5,)bral discs, ligaments and synovial joints (Fig.-2-5)Anterior longitudinal ligAnnulus fibrosusNucleus pulposusVertebral foramenPosterior longitudinal lig.Ligamenta flavaFig. 1-2-5 The intervertebral discThe intervertebral discs vary in shape; size, and1) Intervertebral diseThe intervertebral disc isthickness, in different regions and within individuala symphysis interposed betweenthe adjacent surfacesdiscs.The shape and size of them correspond with theofthevertebral bodiesfromC2tothesacrum.ExceptSurfaces of the bodies between which theyare placed.at the sites of the uncovertebral joints of Luschka,Discs are thinnest in the upper thoracic region anddisc outlines correspond with the adjacent bodies.thickest in the lumbar region They are thicker in ante-Each intervertebral disc is composed, at the circum-rior part than posterior in cervical and lumbar regions,ference, of a tough lamellated fbrocartilaginous ringcontributing to the anterior convexities of these partscalled the annulus fibrosus and in the center, of aofthe column,but nearly uniform in thoracic regionmore pliable gelatinous mass named the nucleus pul-where the anterior concavity is largely due to the ver-posus (Fig.I-2-5).tebral bodies.The intervertebral discs constitute aboutThe nucleus pulposus ishighly plasticandistheone-fourth of the length of the vertebral column; theremainderof the notochord in embryo.The annuluscervical and lumbar portions have a much greaterfibrosus insert frmly into the brims ofthe upper andamount than the thoracic region,with the result thatlower surfaceoftheertebralbodyThesebrocartthese parts possess greater pliancy and freedom oflaginousrngs arecomposedofdensecollagenfbersmovement.rdarinra2)Anterior longitudinal ligament The anteriorintervertebral discs areimportant shockaborberslongitudinal ligament is a broad and strong band ofUnderpreurethehighlyelasticnucleus pulposusfibers,which extends along the anterior surfaces ofbomsfltterandbrader,ndpushsthmothe vertebral bodies and intervertebral discs from theresistant aulus fbrosus inalldirections.Therelabase of the skull to the pelvic surface of the first ortivelythinposteriorparofthannulusfbrosusmaysecond sacral vertebra. It is the longest ligament ofuptureetherduetotraumaortodegenerativechangthe body and broader below than above, thicker inauthoracic than in cervical and lumbar regions. The lig-ament is intimately adhered to the intervertebral discsdidestadand prominent margins of the vertebrae,but not to theamiddle parts of the bodies.This strong ligament mayofback20口扫描全能王创建
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·62·PARTI LOCOMOTORSYSTEMand thicker in thoracic than the cervical and lumbarprevent hyperextension of the vertebral column and isregions.Thisligamenttendstocheckthefexionandespecially important in the lumbar region, where theprevent hyperfexion ofthe vertebral column (Fig.l-2.weight of thebodytends to increasethenormal posture7)ofextensionofthelumbarspine(Fig.1-2-6,7)2.Joints of vertebral archesIntervertebralforamenInf.costalfoveaThe vertebral arches are connected by synovial4Sup.costal foveajoints between articular processes and by accessoryligaments that connect the laminae and all processes.Transverse castalfovea1) Zygapophysial jointsThe zygapophysialjoints are formed by opposing articular processes ofthe adjacent vertebrae.They are mostly of the glidingZygapophysialtype and move only slightly (Fig.1-2-6, 7) .joint2) Ligamenta flavaThe ligamenta fava con.nect laminae of adjacent vertebrae in the vertebral ca-nal.They are thick,yellow andelastic plates,descendfrom the lower anterior surface of one lamina to theFig.I-2-6 The joints of the vertebraeposterior surface and upper margin of the laminabelow, and extend from-zygapophysial joint capsules3)Posteriorlongitudinal ligamentTheposte-to the point where laminae fuse to form spines.It isrior longitudinal ligament is a narrowband lying oncontributed to part of the posterior boundary of thetheposteriorsurfaces ofthevertebral bodiesanddiscsvertebral canal and tends to prevent hyperflexion ofin the vertebral canal, attached between the body ofthe vertebral column.So it is the strongest and mostC2 and the sacrum,and continuous with the tectorialimportant ligament (Fig.1-2-5,7)membrane above. It is broader above than below,Posterior longitudinal lig.Nucleus pulposusIntervertebralforamenMCAnnulus fibrousACLInterspinous lig.aSpinous process物Intervertebral discLigamenta flaSupraspinous ligAnterior longitudinal lig.Fig.I-2-7 The joint and ligaments of the vertebrae3) Interspinous ligamentsThe interspinous lig-behind (Fig.I-2-7).aments are thin and membranous, which connect ad.4)Intertransverse ligamentsjoining spinous processes and extend ventrally fromThe intertrans-verse ligaments connt succeeding transverse prothe root to the apexof each process.They meet thecess and are functionally insignificantligamentafava infontand the supraspinalligament5) Supraspinal ligament (Fig.I-2-5, 7)The口S格扫描全能王创建合品
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Chapter2Arthrology .63supraspinal ligament isastrongfbrous cord,whichJoints of the atlas with the二conncts togethertheapicesofthespinousprocssesaxisfrom the seventh cervicalvertebratothesacrum.Itis continued upwardtotheexternaloccipital protuThe articulation of the atlas with the axis is aberanceandmediannuchalline,astheligamentumcomplicated nature,comprising four distinct joints.Except for the lateral atlantoaxial joints between thenuchae.6) Ligamentum nuchae The ligamentum nu-articular processes of the atlas and axis on both sides,chae isatiangularfbrous membrane, which extendsthere is a median atlantoaxial joint between the densfrom theexternaloccipitalprotuberanceandmediof the axis and the ring formed by the anterior archan nuchal line above, to the spinous process of theand the transverse ligament of atlas.The median atseventh cervical vertebra below, and tips of cervicallantoaxial joint includes two parts:One between thespinous process infront,Itformsamedian septumdental fovea and the dens, the other between the antebetween the musclesoneithersideoftheneck.Inhu-rior surface of the transverse ligament and the back ofman it is merely the rudiment of an important elasticthe dens.ligament, but in some of the lower animals, whichThe median atlantoaxial joint is reinforced by theserves to sustain the weight of the head.apical ligamentofdens,alarligaments and transverse7) Intertransverse ligaments The intertrans-ligamentof atlas (Fig.1-2-8):verse ligaments are interposed between the transverseprocesses.Basilarpart of occipital boneApical ligamentof densOccipital boneAlarligAtlautooccipital joint小鸟Transverselig,of atlasLateral atlantoaxial jointTectorialmembraneAxisFig.I-2-8Ligaments of atlantoaxial and atlantooccipital jointsIt is a thick3)Transverse ligament of atlasI) Apical ligament of dens It extends from theand strong band, which firmly attached to either me-tipof dens to the anterior margin of foramen magdial sides of the lateral mass of the atlas, and retainsum beingintimately bend withthedporiothe dens in contact with the anterior arch. As it cross-theanterioratlantoocipitalmmbranandsuperoes the dens,a small fasciculus prolongs upward, andcrusofthe transverseligamentofatlasanother downward from the superficial or posterior2)AlarligamentsThey arise fromeachsideoffibers of the ligament. The former is attached to thethperardnadpasbiquelyadbasilar part of the occipital bone, in close relatione asisowith the tectorial membrane; the latter is fixed to thetal condyles.口口扫描全能王创建D
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