Thorax23THORACICWALLRibsRibs:SerratusposteriorsuperiorLevatorescostarumTransversusInnermostthoracisintercostalSerratusposteriorinferiorSubcostalesExternalPosterior ViewAnteriorViewintercostalManubriumExternal intercostal membraneMusclesremovedBodyofsternumExternal intercostalInternal intercostalInternalintercostalLateral View1.20MUSCLESOETHORACICWALLTABLE1.1MUSCLESOFTHORACICWALLMuscleSuperiorAttachmentInferior AttachmentInnervationActionExternal intercostalElevate ribsInternal intercostalInferior border of ribsSuperiorborderof ribbelowDepress ribsProbably elevate ribsInnermost intercostalIntercostalnerveTransversus thoracisPosterior suriace of lower sternumDepress ribsIntermal surface ofcostal cartilages 2-6SubcostalesinternalsurfaceoflowerribsneartheiranglesSuperiorbordersof2ndor3rdribsbelowElevate ribsLevatorescostarumTransverseprocessesofC7-T11SubjacentribsbetweentubercleandanglePosteriorramiofC8-T11nervesSerratus posterior superiorNuchal ligament,spinous processesof C7-T3Superior borders of 2nd-4th ribsSecondtofifthintercostalnervesDepress ribsInferior borders of 8th-12th ribs near theirSerratus posterior inferiorSpinous processes ofT11-L2Anterior rami ofT9-T12nervesanglesThetonusof llintercostalmuscleskeepintercostalspaces rigid,thereby preventingthemfrombulging out during expirationandfrom beingdrawninduring inspirationRoleofindividualintercostalmuscles and accessorymuscles of respiration in moving theribs is difficult.to interpretdespite many electromyographic studies.Theroleoftherespiratory muscles dependson which accessory muscles are contracting at the same time
Innermost intercostal Transversus thoracis S t e r n u m Subcostales Anterior View Ribs: Serratus posterior superior Serratus posterior inferior Levatores costarum Posterior View Ribs: External intercostal Muscles removed Internal intercostal External intercostal External intercostal membrane Body of sternum Internal intercostal Manubrium Lateral View 1 1 2 2 1 2 3 3 4 4 5 5 6 6 7 7 8 8 9 9 10 10 11 12 3 4 5 6 7 8 9 10 11 12 1 1 2 2 1 2 3 3 4 4 5 5 6 6 7 7 8 8 9 9 10 10 11 12 3 4 5 6 7 8 9 10 11 12 Agur_Chap01.indd 23 11/14/2011 2:44:39 PM
24THORACICWALLClavicular headSternocleidomastoidStemalheadAxillary veinSubclaviusAxillary artery Posterior.Brachial plexusScaleneMiddlePectoralis minorAnteriorCommon origin ofSubclavian veincoracobrachialis andshort head of biceps brachiiSternothyroidStemohyoidTendon of long head of1st intercostal nervebiceps brachiiParasternallymphnode2nd intercostal nervePectoralismajorveinInternal thoracicartery3rd costal cartilageExternal intercostal4th ribarteryAnteriorintercostalveinInternal intercostalInternal intercostaldeep to externalintercostal membraneSerratus anteriorPectoralis majorTransversus thoracisExternal oblique -Rectus abdominis 8th costal cartilageAnterior View1.21EXTERNALASPECTOFTHORACICWALLH-shaped cuts were made through the perichondrium of the 3rd and 4thThesubclavianvesselsare"sandwiched"betweenthe1stribandclaviclecostalcartilagestoshelloutsegmentsofcartilage.Duringsurgery,retainandare"paddedbythesubclavius.ingperichondriumpromotesregrowthofremovedcartilagesSurgical access to thorax.To gain access to the thoracic cavityThe internal thoracic (internal mammary)vessels run inferiorly deep toforsurgical procedures,thesternum is dividedin themedianplanethecostal cartilagesand justlateral tothe edge ofthesternum,providing(mediansternotomy)andretracted(spreadapart).Aftersurgery,theanteriorintercostalbranches.halvesofthesternumareheldtogetherwithwirestructuresTheparasternallymphnodes(green)receivelymphaticvesselsfromtheanteriorparts of intercostal spaces,thecostal pleura and diaphragm,andthemedialpartofthebreast
Posterior Axillary vein Serratus anterior Transversus thoracis Internal intercostal deep to external intercostal membrane Internal intercostal External intercostal artery Parasternal lymph node 1st intercostal nerve Sternothyroid Subclavian vein Anterior Scalene Middle 2nd intercostal nerve 3rd costal cartilage 4th rib vein External oblique Sternocleidomastoid Subclavius Pectoralis minor Pectoralis major Pectoralis major Tendon of long head of biceps brachii Common origin of coracobrachialis and short head of biceps brachii 8th costal cartilage Rectus abdominis Brachial plexus Axillary artery Sternohyoid Internal thoracic vein Anterior intercostal artery Anterior View Clavicular head Sternal head Agur_Chap01.indd 24 11/14/2011 2:44:42 PM
Thorax25THORACICWALLSternohyoidSternothyroidSubclavian arteryAnterior scaleneBrachiocephalic vein1stribInternalthoracicveinIntemal thoracic artery2nd rib2nd intercostal nerveAnteriorintercostalveinInternalintercostalAnteriorintercostalarteryInternal intercostalBody ofsternumTransversus thoracisDiaphragm-Xiphoid processTransversusabdominisTransversus abdominisPosterior View1.22INTERNALASPECTOETHEANTERIORTHORACICWALL●The inferior portions of the internal thoracic vessels are covered posteriorly by the transversus thoracismuscle:thesuperiorportionsareincontactwiththeparietalpleura(removed)Thetransversusthoracis muscle(superiorto diaphragm)iscontinuouswiththetransversusabdominismuscle(inferiortodiaphragm):theseformtheinnermostlayerofthethreeflatmusclesofthethoracoab-dominal wall.The intemalthoracic(internalmammary)arteryarisesfromthesubclavianarteryand isaccompaniedbytwovenaecomitantesuptothe2ndcostalcartilaqeinthisspecimenandsuperiortothis,bythesingleinternalthoracicveinwhichdrainsintothebrachiocephalicvein
Sternohyoid Subclavian artery Brachiocephalic vein Internal thoracic vein 2nd intercostal nerve Internal intercostal Transversus abdominis Transversus thoracis Anterior scalene Sternothyroid 1st rib 2nd rib Anterior intercostal vein Diaphragm Body of sternum Posterior View Internal thoracic artery Anterior intercostal artery Transversus abdominis Xiphoid process Internal intercostal Agur_Chap01.indd 25 11/14/2011 2:44:48 PM
26THORACICWALLSternalheadSternocleidomastoidPosterior Clavicular headScaleneMiddleAnterior1st ribManubrium of sternumClavicle2nd rib.External intercostalSerratusposteriorsuperiorInterchondral partof internal intercostalCostal cartilageInterosseous partofinternal intercostalCentral tendonof diaphragmRectusabdominisDiaphragmExtermal obliqueVertebral attachmentof diaphragmInternal obliqueCostalTransversusabdominismargin1.23MUSCLESOFRESPIRATIONTABLE1.2MUSCLESOFRESPIRATIONInspirationExpirationNormal (Quiet)MajorDiaphragm (Active Contraction)Passive (Elastic) Recoil of Lungs and Thoracic CageMinorToniccontractionofexternalintercostalsandinterchondralToniccontractionofmusclesofanterolateralabdominalwalls(rectusabdominisexternalandinternalportionof internal intercostalstoresistnegativepressureobliques,transversusabdominis)toantagonizediaphragmbymaintainingintra-abdominalpressureActive (Forced)Inadditiontotheabove,active.contractionofsternocleido-Inadditiontotheabove,activecontractionofmusclesofanterolateralabdominal wall (antagonizingmastoid,descending (superior) trapezius,pectoralis minor,diaphragmbyincreasingintra-abdominaipressureandbypullinginferiorlyandfixing inferiorcostaland scalenes, to elevate and fix upper rib cagemargin):rectusabdominis,externalandinternalobliques,andtransversusabdominisExternal intercostals,interchondralportionofinternalInternalintercostal(interosseouspart)andserratusposteriorinferiortodepressribsintercostals,subcostales,levatores costarum,andserratusposteriorsuperior toelevateribsRecent studies indicate that the serratus posterior superior and inferior muscles may serve primarilyas organs ofproprioception rather than motion
Agur_Chap01.indd 26 11/14/2011 2:44:57 PM
Thorax27THORACICCONTENTSRight vagus nerveIintermal jugular veinTracheaRight subclavian arteryLeft subclavian veinRight subclavian veinApex of left lungRight brachiocephalic veinLeft brachiocephalic veinRight phrenic nerveLeft vagus nerveArchofaortaSuperior lobe of right lungSuperior lobe of left lungLeft phrenic nerveSuperiorvena cavaRoot of lungParietal layer of serous pericardiumCostal surface of lungFibrous pericardium and mediastinaHorizontal fissurepart of parietalpleuraMiddle lobe of right lungMediastinal surface of lungOblique fissureOblique fissureLingulaInferior lobe of left lungInferior lobe of right lungStemocostal surfaceof heartcovered with visceral layerof serouspericardiumDiaphragmAAnteriorView1.24THORACICCONTENTSINSITUThefibrous pericardium, lined by the parietal layer of serous pericardium, is removed anteriorly to exposetheheartandgreatvessels.Therightlunghasthreelobes,thesuperiorlobeisseparatedfromthemiddlelobebythehorizontalfissureandthemiddlelobeis separated fromthe inferiorlobe by theobliquefissure.Theleftlung has two lobessuperiorandinferiorseparatedbytheobliquefissureTheanteriorborderof the left lung isreflected laterally to visualize thephrenic nervepassing anteriortothe root of the lung and the vagus nerve lying anterior to the arch of the aorta and then passing posteriorto the root of the lung.Astherightvagusnervepassesanteriortotherightsubclavian artery.itgivesrisetotherecurrentbranchandthendividestocontributefiberstotheesophageal,cardiac,andpulmonaryplexuses
Left brachiocephalic vein Right subclavian artery Left vagus nerve Arch of aorta Left phrenic nerve Superior lobe of left lung Parietal layer of serous pericardium Oblique fissure Inferior lobe of left lung Diaphragm Inferior lobe of right lung Oblique fissure Middle lobe of right lung Horizontal fissure Superior lobe of right lung Right vagus nerve Costal surface of lung Trachea Apex of left lung Root of lung Mediastinal surface of lung Lingula Anterior View Right phrenic nerve Fibrous pericardium and mediastinal part of parietal pleura Sternocostal surface of heart covered with visceral layer of serous pericardium Left subclavian vein Superior vena cava Right brachiocephalic vein Right subclavian vein Internal jugular vein Agur_Chap01.indd 27 11/14/2011 2:45:01 PM