18BONYTHORAXANDJOINTSANTERIORPOSTERIORAnterior longitudinal ligamentRadiate ligamentof head of ribSuperiorcostotransverseligamentIntra-articular ligamentPlane of section for BA. Lateral ViewSuperiorarticular processPOSTERIORLateralcostotransverseTransverse processligamentCostotransversejoint75CostotransverseligamentRibRadiate ligament ofhead of ribJointofheadofribVertebral bodyB. Superior ViewANTERIOR1.15LIGAMENTSOFCOSTOVERTEBRALARTICULATIONSA. External and internal ligaments.B. Transverse sectioneTheradiateligamentjoinstheheadoftheribtotwovertebralbodiesandThevertebralbody,transverseprocesses,superiorarticulatingprocessestheinterposedintervertebraldiscandposteriorelementsofthearticulatingribshavebeentransverselysec-Thesuperiorcostotransverseligament joinsthecrestof theneckoftheribtionedtovisualizethejointsurfacesandligamentstothetransverseprocessaboveThecostotransverse ligament joinstheposterioraspectoftheneckoftheThe intra-articular ligament joins the crest of the head of the rib to therib to the adjacent transverse process.Thelateral costotransverse ligament joins thenonarticulatingpartof theintervertebraldisc.tubercleoftheribtothetip(apex)ofthetransverseprocess
A. Lateral View Intra-articular ligament POSTERIOR ANTERIOR Anterior longitudinal ligament Radiate ligament of head of rib Superior costotransverse ligament B. Superior View Lateral costotransverse ligament POSTERIOR Transverse process Rib ANTERIOR Costotransverse ligament Vertebral body Costotransverse joint Joint of head of rib Plane of section for B Radiate ligament of head of rib Superior articular process Agur_Chap01.indd 18 11/14/2011 2:44:23 PM
Thorax19THORACICWALLAnterior ramusTransverseprocessof thoracic nervePosterior ramusSuperior costotransverse ligamentSpinal ganglionExternal intercostalInnermost intercostalRadiate ligament of head of ribSubcostalesIntermal intercostalmembraneveinPosterior intercostaarteryAnterior longitudinal ligamentIntercostal nerveCollateral branches of intercostalvessels and nerveRami communicantesSplanchnic nerveSympathetic trunkAnterior View1.16VERTEBRALENDSOFINTERNALASPECTOFINTERCOSTALSPACESPortionsofthe innermostintercostal musclethatbridgetwointercostal spaces are calledsubcostalesmusclesTheinternal intercostalmembrane,inthemiddlespace,iscontinuousmedialywiththesuperiorcosto-transverse ligament.Notethe orderofthestructures in themost inferior space:posterior intercostal veinandartery,and inter-costalnerve;notealsotheircollateralbranches·The anterior ramus crosses anteriorto thesuperiorcostotransverse ligament;the posterior ramus is pos-terior to it.The intercostalnerves attach to thesympathetictrunkbyrami communicantes;the splanchnic nerve isavisceralbranchofthetrunk
Collateral branches of intercostal vessels and nerve Intercostal nerve Internal intercostal membrane Subcostales Innermost intercostal Splanchnic nerve Sympathetic trunk Rami communicantes Anterior ramus of thoracic nerve Posterior ramus Spinal ganglion Radiate ligament of head of rib Anterior longitudinal ligament Transverse process External intercostal Superior costotransverse ligament Anterior View artery vein Posterior intercostal Agur_Chap01.indd 19 11/14/2011 2:44:26 PM
20THORACICWALLLongissimusIliocostalisLevatores costarum7th ribAngle of 8th ribPosterior ramus of thoracic nervePosterior intercostal vessels and intercostal nerve,posterior to transparent parietal pleura covering the lungCollateral branch of intercostal nerveLateralcostotransverseligamentInnermost intercostalInternal intercostalSemispinalisTip of transverseprocessExternalInternal intercostalmembraneintercostalPosterior Viewofthe10thintercostalspace1.17VERTEBRALENDSOFEXTERNALASPECTOFINFERIORINTERCOSTALSPACESTheiliocostalisandlongissimusmuscleshavebeenremoved.exposinathelevatorescostarummuscle.Ofthefive intercostal spacesshown,thesuperiortwo (6thand7th)areintact.Inthe8thand1Othspacesvarying portions of the extemal intercostal muscle have been removed to reveal the underlying intemalintercostalmembrane,whichis continuous withthe internal intercostalmuscle.Inthe9thspace,theleva-torescostarummusclehasbeenremovedtoshowtheposteriorintercostalvesselsandintercostalnerveThe intercostal vesselsand nervedisappearlaterallybetween the internal and innermostintercostalmuscles.The intercostal nerve isthe most inferiorof theneurovasculartrio (posterior intercostal vein and arteryandintercostal nerve) and the least sheltered in the intercostal groove; a collateral branch arises near the angleoftherib.Thoracocentesis.Sometimesitisnecessaryto insertahypodermicneedlethroughanintercostalspaceintothepleuralcavity(seeFig.1.27)toobtainasampleofpleuralfluidortoremovebloodorpus.Toavoiddamagetotheintercostalnerveandvessels.theneedleisinsertedsuperiortotherib,highenoughtoavoidthecollateralbranches
Tip of transverse process Internal intercostal membrane of the 10th intercostal space Levatores costarum Lateral costotransverse ligament Angle of 8th rib Posterior ramus of thoracic nerve Posterior intercostal vessels and intercostal nerve, posterior to transparent parietal pleura covering the lung Collateral branch of intercostal nerve Innermost intercostal Internal intercostal External intercostal Semispinalis 7th rib Iliocostalis Longissimus Posterior View Agur_Chap01.indd 20 11/14/2011 2:44:29 PM
ThoraxTHORACICWALL21Lateral cutaneous branchof intercostal nerveExtemal intercostal9th ribInternal intercostalInnermost intercostalInternal intercostalRectusabdominis10th intercostal nerveTransversusabdominis Internal obliqueExternal obliqueAnterior View1.18ANTERIORENDSOFINFERIORINTERCOSTALSPACES?ThefibersoftheextemalintercostalandexternalobliquemusclesruninferomediallyTheinternal intercostalandinternalobliquemusclesareincontinuityattheendsofthe9th,1Oth,and11thintercostalspaces.Theintercostalnervesliedeeptotheinternalintercostalmusclebutsuperficialtotheinnermostintercostalmuscle:anteriorlythesenervesliesuperficialtothetransversusthoracisortransversusabdomi-nismuscles.Intercostal nerves runparallel to theribsandcostal cartilages;on reaching theabdominal wall,nerves T7 andT8 continue superiorty.T9 continues nearly horizontally,and T10 continues inferomedially toward the umbili-cus.Thesenervesprovidecutaneous innervation inoverlappingsegmentalbands
Innermost intercostal Lateral cutaneous branch of intercostal nerve External intercostal Internal intercostal 10th intercostal nerve Internal intercostal Internal oblique Transversus abdominis Rectus abdominis External oblique 9th rib Anterior View Agur_Chap01.indd 21 11/14/2011 2:44:33 PM
22THORACICWALLPosterior ramusPosteriorbranch ofposterior intercostal arteryAnterior ramus(intercostal nerve)Intermal intercostalmembranePosteriorintercostalarteryExternal intercostalLateral pectoralcutaneousbranchParietal pleura/ Lateral pectoral cutaneous branch(cut edge)AortaSympathetic trunkRamicommunicantesSite of anastomosis/potentialIntemalintercostal-Innermost intercostalcollateral pathway betweenposterior and anteriorCommonmembraneof innermostintercostal arteriesintercostalandtransversusthoracisTransversus thoracisExternal intercostal membraneAnteriorintercostalarteryTransverse SectionInternal thoracic arteryAnteriorpectoral cutaneousbranchAnterior perforating branch1.19CONTENTSOFINTERCOSTALSPACE.TRANSVERSESECTIONThediagram is simplified byshowingnerves on theright andarterieson the left.The three musculomembranous layers are the external intercostal muscle and membrane, internal inter-costalmuscleandmembrane.andtheinnermostintercostalmuscle,transversusthoracismuscle.andthemembraneconnectingthemThe intercostal nervesaretheanterior ramiof spinal nervesT1toT11:theanteriorramusof T12 is thesubcostal nerve.Posterior intercostal arteries are branches of theaorta (the superior two spaces are supplied from thesuperiorintercostal branchofthecostocervical trunk):theanterior intercostalarteriesarebranchesof theinternalthoracicarteryoritsbranch,themusculophrenicartery.Theposteriorrami innervatethedeepbackmusclesandskinadjacenttothevertebralcolumn
Posterior ramus Posterior branch of posterior intercostal artery Posterior intercostal artery Aorta Lateral pectoral cutaneous branch Anterior intercostal artery Internal thoracic artery Anterior perforating branch Transversus thoracis Anterior pectoral cutaneous branch External intercostal membrane Innermost intercostal Internal intercostal Lateral pectoral cutaneous branch External intercostal Internal intercostal membrane Anterior ramus (intercostal nerve) Parietal pleura (cut edge) Sympathetic trunk Common membrane of innermost intercostal and transversus thoracis Rami communicantes Transverse Section Site of anastomosis/potential collateral pathway between posterior and anterior intercostal arteries Agur_Chap01.indd 22 11/14/2011 2:44:36 PM