Download Vertebrae

THEBACK
VERTEBRAE
VERTEBRALCOLUMN
TOPICS
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THEBONESandTHEJOINTSOFTHEBACK
THETYPICALVERTEBRA
THEINTERVERTEBRALDISC
THECERVICALVERTEBRAE
THETHORACICVERTEBRAE
THELUMBARVERTEBRAE
THESACRUM
THECOCCYX
THEJOINTSOFVERTEBRALCOLUMN
THELIGAMENTSOFVERTEBRALCOLUMN
THECURVATURESOFVERTEBRALCOLUMN
THEVASCULATUREOFVERTEBRALCOLUMN
THELEVELCORRESPONDINGSTRUCTURE
THEVERTEBRAE
THEBONES
and
THEJOINTSOFTHEBACK
THEBACK-BONES&JOINTS
THEBACK
Thebackcomprisestheposterioraspectofthetrunk,inferior
totheneckandsuperiortothebuMocks.
Thevertebralcolumnextendsfromthecranium
(skull)totheapexofthecoccyx.
THEVERTEBRAE
Thevertebralcolumninanadultconsistsof
33vertebraearrangedinfiveregions:
•  7cervicalC1-C7
•  12thoracicT1-T12
•  5lumbarL1-L5
•  5sacralS1-S5
•  4coccygeal
THEBACK-BONES&JOINTS
THEVERTEBRAE
THEBACK-BONES&JOINTS
Significantmo]onoccursonlybetweenthe
25superiorvertebrae.
Ofthe9inferiorvertebrae,the5sacralvertebraeare
fusedinadultstoformthesacrum,anda`er
approximatelyage30,the4coccygealvertebraefuse
toformthecoccyx.
THEBACK-BONES&JOINTS
THEVERTEBRAE
THETYPICALVERTEBRA
THEVERTEBRAE
THEBACK-BONES&JOINTS
Atypicalvertebraconsistsofa:
•  vertebralbody
•  vertebralarch
•  sevenprocesses
Thevertebralbodyisthemoremassive,cylindrical,anteriorpartof
thebonethatgivesstrengthtothevertebralcolumnandsupports
bodyweight.
Thevertebralarchisposteriortothevertebralbodyandconsistsof2
(rightandle`)pediclesand2laminae.
Thevertebralarchandtheposteriorsurfaceofthevertebralbody
formthewallsofthevertebralforamen.
THEVERTEBRAE
THEBACK-BONES&JOINTS
Thevertebralarchenclosesthevertebral(foramen)canalthathouses
thespinalcord.
Thecanalcontainsthespinalcordandtherootsofthespinalnerves,
alongwiththemembranes(meninges),fat,andvesselsthatsurround
andservethem.
THEBACK-BONES&JOINTS
THEVERTEBRAE
Vertebralnotchesofadjacent
pediclesformintervertebral
foraminathatprovidefortheexit
ofthespinalnerves.
Thedorsalprojec]ngspinesand
thelateralprojec]ngtransverse
processesprovideaRachment
sitesformusclesandligaments.
THEVERTEBRAE
THEBACK-BONES&JOINTS
Sevenprocessesarisefromthevertebralarchofatypical
vertebra:
•  Onemedianspinousprocessprojectsposteriorlyfromthevertebral
archatthejunc]onofthelaminae.
•  Twotransverseprocessesprojectposterolaterallyfromthe
junc]onsofthepediclesandlaminae.
•  FourarScularprocesses:twosuperiorandtwoinferioralsoarise
fromthejunc]onsofthepediclesandlaminae,eachbearingan
ar]cularsurface(facet).
THEVERTEBRAE
THEBACK-BONES&JOINTS
Thear]cularprocessesareinapposi]onwithcorresponding
processesofvertebraeadjacent(superiorandinferior)tothem,
formingzygapophysial(facet)joints
Theintervertebraldiskscontributetoabout25%ofthelengthofthe
vertebralcolumn.
Theyformthecar]laginousjointsbetweenthevertebralbodiesand
providelimitedmovementsbetweentheindividualvertebrae.
THEBACK-BONES&JOINTS
THEINTERVERTEBRALDISK
THEVERTEBRAE
Eachintervertebraldiskisnumberedbythe
vertebralbodyabovethedisk.
THEBACK-BONES&JOINTS
THEVERTEBRAE
Eachintervertebraldiskis
composedofthefollowing:
•  Anulusfibrosusconsistsof
theouterconcentricringsof
fibrocar]lageandfibrous
connec]ve]ssue.
•  Nucleuspulposusisan
innerso`,elas]c,
compressiblematerialthat
func]onsasashock
absorber
THEBACK-BONES&JOINTS
Thehernia]onofa
nucleuspulposusismost
commonlyina
posterolateraldirecSon
duetothestrengthand
posi]onoftheposterior
longitudinalligament
THEBACK-BONES&JOINTS
CERVICALVERTEBRAE
THENECK
THENECK-BONES&JOINTS
7cervicalvertebraeformthecervicalregionofthevertebralcolumn,
whichenclosesthespinalcordandmeninges.
CERVICALVERTEBRAE-CHARACTERISTICS
-thesmallestofthe24movablevertebrae
-themostdis]nc]vefeatureofeachcervicalvertebraistheoval
foramentransversarium(transverseforamen)inthetransverse
process
THENECK-BONES&JOINTS
THECERVICALVERTEBRAE
Themostdis]nc]vefeatureofeachcervicalvertebrais
theovalforamentransversarium(transverseforamen)inthe
transverseprocess.
THENECK
THENECK-BONES&JOINTS
THECERVICALVERTEBRAE
ThefourtypicalcervicalvertebraeC3–C6havethefollowing
characteris]cs:
•  Thevertebralbodyissmallandlongerfromsidetosidethan
anteroposteriorly;thesuperiorsurfaceisconcave,andtheinferior
surfaceisconvex.
•  Thevertebralforamenislargeandtriangular.
•  Thetransverseprocessesofallcervicalvertebrae(typicalor
atypical)includeforaminatransversariaforthevertebralvessels
(thevertebralveinsand,exceptforvertebraC7,thevertebral
arteries).
•  Theirspinousprocessesareshortandbifid.
•  Thetransverseprocessesofcervicalvertebraeendlaterallyintwo
projec]ons:ananteriortubercleandaposteriortubercle.The
anteriorramiofthecervicalspinalnervescourseini]allyonthe
transverseprocessesingroovesforspinalnervesbetweenthe
tubercles.
THENECK-BONES&JOINTS
THECERVICALVERTEBRAE
Thefirst(atlas),second
(axis)andseventh
(vertebraprominens)
cervicalvertebraeare
ATYPICAL.
VertebraeC3–C6arethe
typicalcervicalvertebrae.
THENECK-BONES&JOINTS
THECERVICALVERTEBRAE
Therearethreeatypicalcervicalvertebrae(C1,C2,andC7):
•  TheC1vertebraoratlas:aring-like,kidney-shapedbonelackinga
spinousprocessorbodyandconsis]ngoftwolateralmasses
connectedbyanteriorandposteriorarches.Itsconcavesuperior
ar]cularfacetsreceivetheoccipitalcondyles.
•  TheC2vertebraoraxis:apeg-likedens(odontoidprocess)
projectssuperiorlyfromitsbody.Thedensisembryologicallythe
vertebralbodyoftheatlas(C1).
THENECK-BONES&JOINTS
THECERVICALVERTEBRAE
Theaxishastwolarge,flatbearingsurfaces,thesuperiorar]cular
facets,onwhichtheatlasrotates.
Thedensliesanteriortothespinalcordandservesasthepivot
aboutwhichtherota]onoftheheadoccurs.
Thedensisheldinposi]onagainsttheposterioraspectofthe
anteriorarchoftheatlasbythetransverseligamentofthe
atlas.
THENECK-BONES&JOINTS
THECERVICALVERTEBRAE
Therearethreeatypicalcervicalvertebrae(C1,C2,andC7):
•  Thevertebraprominens(C7):so-namedbecauseofitslong
spinousprocess,whichisnotbifid.Itstransverseprocessesare
large,butitsforaminatransversariaaresmall.
THENECK-BONES&JOINTS
THECERVICALVERTEBRAE
Therearethreeatypicalcervicalvertebrae(C1,C2,andC7):
•  TheC1vertebraoratlas:aring-like,kidney-shapedbonelackinga
spinousprocessorbodyandconsis]ngoftwolateralmasses
connectedbyanteriorandposteriorarches.Itsconcavesuperior
ar]cularfacetsreceivetheoccipitalcondyles.
•  TheC2vertebraoraxis:apeg-likedens(odontoidprocess)
projectssuperiorlyfromitsbody.
•  Thevertebraprominens(C7):so-namedbecauseofitslong
spinousprocess,whichisnotbifid.Itstransverseprocessesare
large,butitsforaminatransversariaaresmall.
CERVICALVERTEBRAE-CHARACTERISTICS
THEBACK-BONES&JOINTS
C7isaprominentvertebrathatischaracterizedbyalongspinous
process-vertebraprominens
THEBACK-BONES&JOINTS
CERVICALVERTEBRAE-CHARACTERISTICS
•  VertebraC1,alsocalledtheatlas,isuniqueinthatithasneithera
bodynoraspinousprocess
•  C1ringshapedbonehaspairedlateralmasses
•  AnteriorandposteriorarchesofC1,eachofwhichbearsatubercle
inthecenterofitsexternalaspect
THEBACK-BONES&JOINTS
CERVICALVERTEBRAE-CHARACTERISTICS
•  vertebraC2,alsocalledtheaxis,isthestrongestofthecervical
vertebrae
•  thedis]nguishingfeatureofC2istheblunttooth-likedens
(odontoidprocess),whichprojectssuperiorlyfromitsbody
•  theaxishastwolarge,flatbearingsurfaces,thesuperiorarScular
facets,onwhichtheatlasrotates
THEBACK-BONES&JOINTS
THORACICVERTEBRAE
THEBACK-BONES&JOINTS
THORACICVERTEBRAE-CHARACTERISTICS
ThethoracicvertebraeprovideaMachmentfortheribs
theprimarycharacteris]cfeaturesofthoracicvertebraearethecostal
facetsforar]cula]onwithribs
Theprimarycharacteris]cfeaturesofthoracicvertebraearethecostal
facetsforarSculaSonwithribs.
THEBACK-BONES&JOINTS
LUMBARVERTEBRAE
THEBACK-BONES&JOINTS
LUMBARVERTEBRAE-CHARACTERISTICS
Thelumbarvertebraehavemassivebodies,accoun]ngformuchof
thethicknessofthelowertrunkinthemedianplane
Aredis]nguishedbytheirlargebodies,sturdylaminae,andabsenceof
costalfacets.
Thefi`hlumbarvertebrahasthelargestbodyofthevertebrae.
Arecharacterizedbyastrong,massivetransverseprocessandhave
mamillaryandaccessoryprocesses.
THEBACK-BONES&JOINTS
SACRUM
SACRUM-CHARACTERISTICS
Thewedged-shapedsacrumisusuallycomposedof
fivefusedsacralvertebraeinadults.
THEBACK-BONES&JOINTS
Thesacralcanalisthecon]nua]onofthevertebralcanalinthe
sacrum
Typicallyfourpairsofsacralforaminafortheexitoftheposteriorand
anteriorramiofthespinalnerves
Thebaseofthesacrumisformedbythesuperiorsurface
oftheS1vertebra.
Theanteriorprojec]ngedgeofthebodyoftheS1vertebrais
thesacralpromontory.
Theapexofthesacrum,itstaperinginferiorend,hasanovalfacetfor
ar]cula]onwiththecoccyx.
THEBACK-BONES&JOINTS
SACRUM-CHARACTERISTICS
Thesacrumis]ltedsothatitar]culateswiththeL5vertebraatthe
lumbosacralangle,whichvariesfrom130°to160°.
Thepelvicsurfaceofthesacrumissmoothandconcave.
Thedorsalsurfaceofthesacrumisrough,convex,andmarkedbyfive
prominentlongitudinalridges
THEBACK-BONES&JOINTS
SACRUM-CHARACTERISTICS
Theclinicallyimportantfeaturesofthedorsalsurfaceofthesacrum
aretheinvertedU-shapedsacralhiatusandthesacralcornua
Thesacralhiatusleadsintothesacralcanal.
Incaudalepiduralanesthesiaorcaudalanalgesia,alocalanestheSc
agentisinjectedintothefatofthesacralcanalthatsurroundsthe
proximalpor]onsofthesacralnerves.
Becausethesacralhiatusislocatedbetweenthesacralcornuaand
inferiortotheS4spinousprocessormediansacralcrest,these
palpablebonylandmarksareimportantforloca]ngthehiatus.
TheanestheScsoluSonspreadssuperiorlyandextradurally,whereit
actsontheS2–Co1spinalnervesofthecaudaequina.
THEBACK-BONES&JOINTS
LUMBARPUNCTURE
Alumbarpunctureisusedtoinjectanesthe]cmaterialintheepidural
spaceortowithdrawCSFfromthesubarachnoidspace.
Aspinaltapistypicallyperformedat
theL4-L5interspace.
Ahorizontallinedrawnatthetopof
theiliaccrestmarkstheleveloftheL4
vertebra.
Whenalumbarpunctureisperformed
inthemidline,theneedlepasses
throughtheinterlaminarspaceofthe
vertebralcolumnfoundbetweenthe
laminaeofthelumbarvertebrae.
Theinterlaminarspaces
arecoveredbythe
highlyelas]c
ligamentumflava.
LUMBARPUNCTURE
THEBACK-BONES&JOINTS
ClinicalCorrelate.Duringalumbarpunctureaneedleispassed
throughtheinterlaminarspacewhilethevertebralcolumnis
flexed.Theneedlepassesthroughthefollowinglayers:
•Skin
•Superficialfascia
•Deepfascia
•Supraspinousligament
•lnterspinousligament
•lnterlaminarspace
•Epiduralspace
•Dura
•Arachnoid
•Subarachnoidspace
THEBACK-BONES&JOINTS
COCCYX
THEBACK-BONES&JOINTS
COCCYX-CHARACTERISTICS
asmalltriangularbonethatisusuallyformedbyfusionof
thefourcoccygealvertebrae
thecoccyxdoesnotpar]cipatewiththeothervertebraeinsupportof
thebodyweightwhenstanding
THEBACK-BONES&JOINTS
VERTEBRALCOLUMN
VERTEBRALCOLUMN
THEBACK-BONES&JOINTS
Thevertebralcolumn(spine)isanaggregatestructure,normally
madeupof33vertebraeandthecomponentsthatunitethemintoa
singlestructural,func]onalen]ty-the“axis”oftheaxialskeleton.
VERTEBRALCOLUMN
THEBACK-BONES&JOINTS
JOINTSOFVERTEBRALCOLUMN
VERTEBRALCOLUMN
THEBACK-BONES&JOINTS
Thejointsofthevertebralcolumnincludethe:
•  Jointsofthevertebralbodies.
•  Jointsofthevertebralarches.
•  Craniovertebral(atlanto-axialandatlanto-occipital)joints.
•  Costovertebraljoints.
•  Sacro-iliacjoints.
VERTEBRALCOLUMN
THEBACK-BONES&JOINTS
Thejointsofthevertebralbodiesaresymphyses(secondary
car]laginousjoints)designedforweight-bearingandstrength.The
ar]cula]ngsurfacesofadjacentvertebraeareconnectedbyIVdiscs
andligaments.
Atypicalvertebrahasatotalofsixjointswithadjacentvertebrae:
•  foursynovialjoints(twoaboveandtwobelow)and
•  twosymphyses(oneaboveandonebelow).
Eachsymphysisincludesanintervertebraldisc.
INTERVERTEBRALDISCS
Stabilizeandmaintainspinebyanchoringadjacentvertebralbodies.
Allowflexibilityandabsorb/distributeenergy.
INTERVERTEBRALDISCS
Thediscsmakeup25%ofthespineheight.Discdegenera]onwith
ageresultsinlossofspinalcolumnheight.
VERTEBRALCOLUMN
THEBACK-BONES&JOINTS
INTERVERTEBRALDISCS
Althoughthemovementbetweenanytwovertebraeislimited,the
summa]onofmovementamongallvertebraeresultsinalargerange
ofmovementbythevertebralcolumn.
Theintervertebraldiscconsistsofanouteranulusfibrosus,which
surroundsacentralnucleuspulposus.
VERTEBRALCOLUMN
THEBACK-BONES&JOINTS
Theanulusfibrosusconsistsofanouterringofcollagen.This
arrangementoffiberslimitsrota]onbetweenvertebrae.
Thenucleuspulposusfillsthecenteroftheintervertebraldiscand
absorbscompressionforcesbetweenvertebrae.
VERTEBRALCOLUMN
THEBACK-BONES&JOINTS
ThereisnoIVdiscbetween
C1andC2
vertebrae.
Themostinferiorfunc]onaldiscisbetween
L5andS1
vertebrae.
VERTEBRALCOLUMN
THEBACK-BONES&JOINTS
Uncovertebral“joints”or
cle`s(ofLuschka)commonly
developbetweentheunciof
thebodiesofC3or4–C6or7
vertebrae.Thejointsareat
thelateraland
posterolateralmarginsof
theIVdiscs.
Theuncovertebral“joints”
arefrequentsitesof
bonespurformaSoninlater
years,whichmaycauseneck
pain.
THEBACK-BONES&JOINTS
VERTEBRALCOLUMN
Theanteriorlongitudinal
ligamentisastrong,broad
fibrousbandthatcoversand
connectstheanterolateral
aspectsofthevertebralbodies
andIVdiscs.
Theligamentextends
longitudinallyfromthepelvic
surfaceofthesacrumtothe
anteriortubercleofvertebra
C1andtheoccipitalbone
Theanteriorlongitudinal
ligamentistheonlyligament
thatlimits
extension.
AllotherIVligamentslimit
formsofflexion.
VERTEBRALCOLUMN
Theposteriorlongitudinal
ligamentisamuchnarrower,
somewhatweakerbandthan
theanteriorlongitudinal
ligament.
ItisaMachedmainlytotheIV
discs.
Helpspreventorredirect
posteriorhernia]onofthe
nucleuspulposus.
THEBACK-BONES&JOINTS
Theposteriorlongitudinal
ligamentrunswithinthe
vertebralcanalalongthe
posterioraspectofthe
vertebralbodies.
VERTEBRALCOLUMN
THEBACK-BONES&JOINTS
Thejointsofthevertebralcolumnincludethe:
•  Jointsofthevertebralbodies.
•  Jointsofthevertebralarches.
•  Craniovertebral(atlanto-axialandatlanto-occipital)joints.
•  Costovertebraljoints.
•  Sacro-iliacjoints.
THEBACK-BONES&JOINTS
VERTEBRALCOLUMN
Thesynovialjointsbetweensuperiorand
inferiorar]cularprocessesonadjacent
vertebraearethezygapophysialjoints.
Thesear]cula]onsareplanesynovialjoints
betweenthesuperiorandinferiorarScular
processesofadjacentvertebrae.
Athinar]cularcapsuleaMachedtothemargins
ofthear]cularfacetsencloseseachjoint.
Thezygapophysialjointspermitgliding
movementsbetweenthear]cularprocesses.
VERTEBRALCOLUMN
THEBACK-BONES&JOINTS
Incervicalregions,thezygapophysialjointsslopeinferiorlyfrom
anteriortoposterior.Thisorienta]onfacilitatesflexionand
extension.
Inthoracicregions,thejointsareorientedver]callyandlimitflexion
andextension,butfacilitaterota]on.
Inlumbarregions,thejointsurfacesarecurvedandadjacent
processesinterlock,therebylimi]ngrangeofmovement
THEBACK-BONES&JOINTS
THELIGAMENTSOFVERTEBRALCOLUMN
VERTEBRALCOLUMN
THEBACK-BONES&JOINTS
Thelaminaeofadjacentvertebralarchesarejoinedbybroad,pale
yellowbandsofelas]c]ssuecalledtheligamentaflava.
Thethininterspinousligamentsconnectadjoiningspinousprocesses,
aMachingfromtheroottotheapexofeachprocess.
Thecord-likebandformingthesupraspinousligamentsconnectsthe
]psofthespinousprocessesfromC7tothesacrumandmerge
superiorlywiththenuchalligamentatthebackoftheneck.
Thestrong,broadnuchalligamentiscomposedofthickened
fibroelas]c]ssue.
Theintertransverseligaments,connec]ngadjacenttransverse
processes.
VERTEBRALCOLUMN
THEBACK-BONES&JOINTS
Thejointsofthevertebralcolumnincludethe:
•  Jointsofthevertebralbodies.
•  Jointsofthevertebralarches.
•  Craniovertebral(atlanto-axialandatlanto-occipital)joints.
•  Costovertebraljoints.
•  Sacro-iliacjoints.
VERTEBRALCOLUMN
THEBACK-BONES&JOINTS
Theatlantooccipitaljoints,formedbetweentheatlas(C1vertebra),
andtheoccipitalboneofthecranium.
Atlanto-occipitalJoints.Thear]cula]onsarebetweenthesuperior
ar]cularsurfacesofthelateralmassesoftheatlasandtheoccipital
condyles.
VERTEBRALCOLUMN
THEBACK-BONES&JOINTS
Atlanto-occipitalJoints.Themainmovementisflexion,withaliMle
lateralflexionandrota]on.
Theatlanto-axialjoints,formedbetweentheatlasandaxis(C2
vertebra).
VERTEBRALCOLUMN
THEBACK-BONES&JOINTS
Atlanto-axialJoints.Therearethreeatlanto-axialar]cula]ons.
Atlanto-axialJoints.Two(rightandle`)lateralatlanto-axialjoints
(betweentheinferiorfacetsofthelateralmassesofC1andthe
superiorfacetsofC2),andonemedianatlanto-axialjoint(between
thedensofC2andtheanteriorarchoftheatlas).
Thelateralatlanto-axialjointsaregliding-typesynovialjoints,
whereasthemedianatlantoaxialjointisapivotjoint.
THEBACK-BONES&JOINTS
THECURVATURESOFVERTEBRALCOLUMN
CURVATURESOFVERTEBRALCOLUMN
Thevertebralcolumninadultshasfour
curvaturesthatoccurinthecervical,thoracic,
lumbar,andsacralregions.
THEBACK-BONES&JOINTS
CURVATURESOFVERTEBRALCOLUMN
cervicallordosis
lumbarlordosis
areconcaveposteriorly
THEBACK-BONES&JOINTS
thoracickyphosis
sacralkyphosis
areconcaveanteriorly
CURVATURESOFVERTEBRALCOLUMN
THEBACK-BONES&JOINTS
Thethoracicandsacralkyphosesareprimarycurvaturesthatdevelop
duringthefetalperiod.
Thecervicaland
lumbarlordosesare
secondary
curvaturesthat
resultfrom
extensionfromthe
flexedfetalposi]on.
THEBACK-BONES&JOINTS
THEVASCULATUREOFVERTEBRALCOLUMN
VASCULATUREOFVERTEBRALCOLUMN
THEBACK-BONES&JOINTS
Vertebraearesuppliedbyperiostealandequatorialbranchesofthe
majorcervicalandsegmentalarteriesandtheirspinalbranches.
Periostealandequatorialbranchesarisefromthesearteriesasthey
crosstheexternal(anterolateral)surfacesofthevertebrae.
Spinalveinsformvenousplexusesalongthevertebralcolumnboth
insideandoutsidethevertebralcanal.
Spinalveinsformvenousplexusesalongthevertebralcolumnboth
insideandoutsidethevertebralcanal.
Thevertebralcolumnisinnervatedby(recurrent)meningeal
branchesofthespinalnerves.
Thezygapophysialjointsisinnervatedbyar]cularbranchesofthe
medialbranchesoftheposteriorrami.
LEVELCORRESPONDINGSTRUCTURE
C2-C3 Mandible
C3
Hyoidcar]lage
C4-C5 Thyroidcar]lage
C6
Cricoidcar]lage
C7
Vertebralprominens
T3
Spineofscapula
T7
Xyphoid,]pofscapula
T10
Umbilicus
L1
Conusmedullaris(endofcord)
L3
Aortabifurca]on
L4
Iliaccrest
THEBACK-BONES&JOINTS