Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Lecture2–ThoracicWallsandBreast Intercostal space Rib/Thoracic cage Thoracic wall (muscle, nerves and vessels) Thoracicwall • Themainfunctionofthethoracicwallistoprotecttheviscera Protects Mechanical basis of within breathing Includes thoracic cage and • Mechanicalbasisofbreathing covering • Thoracicwallincludesthoraciccage(ribs,sternumand Intercostal muscles vertebra)andcovering(skinandmuscle) Subcutaneous fat Superficial fascia Deep Fascia Skin Pectoralis Major sweat glands, fat, blood (superficial muscles) and lymphatic vessels, nerves, the mammary Thoraciccage gland. Ribs • Thereare12ribsandeachoftheseribsareassociatedwithacostalcartilage(anteriorly).Andthesecostal cartilagesattachtheeachoftheribstothesternumanteriorly. • Thecostalcartilageismovablesotheyareveryimportantformobilityofthethoraciccage(allowsitto expandinbreathing) • Theribscanbeclassifiedviavarioussystems Costal cartilage Rib o True,false,floating Ribs Attaches ribs to § Ribs1-7=trueribs sternum anteriorly • Eachofthemattachdirectly Contributes to mobility of thoracic Ribs 1-7 (True ribs) tothesternumviathereown cage Attach directly to sternum via costalcartilage costal cartilage § Ribs8-10=falseribs • Eachofthemattachtothe Intercostal costalcartilageoftherib spaces aboveit(nodirect Ribs 11 and 12 (Floating ribs) attachmenttothesternum) Have no anterior § Ribs11-12=floatingribs attachment Ribs 8-10 (False ribs) • Theyhavenoanterior Attach to costal cartilage of attachmentatall rib above o Typicaloratypical Typical ribs (3-9) Atypical ribs (1, 2, 10-12) Curved and flat § Ribs3-9=typicalribs Different markings Superior facet • Theyhaveallthesortsof featuresthatmostoftheribs Head Inferior facet Neck Articular facet have Angle Tubercle Grooves for • Curvedandflat subclavian vessels • Therearesomelumps particularlyintheposterior Costal groove Scalene tubercle endthatarerelevantfor Shaft Superior view articulationwiththevertebra of rib 1 andforboththebodyofthe Posterior view Inferior view vertebraandthetransverse processes • Thereisagroovearoundmostoftheshaftoftheribandthisiscalledthecostal groove.Thisgroovesheltersandprotectstheintercostalvein,arteryandnervesin theintercostalspace. • Posteriorend o thereare2articularprocessescalledfacets.Thereisaninferiorandsuperior facet.Thesefacetsarticulatewiththebodyofthevertebra. § Superiorfacetarticulateswithinferiordemifacetofthebodyof vertebraandtheinferiorfacetarticulateswiththesuperior demifacetofthebodyofthevertebrabelow o Thereisanarticularfacetandtuberclejustlateraltotheneck. § Thearticularfacetisusedforthearticulationwiththetransverse processofthevertebra.So,theheadofeachribarticulateswiththe Netter, F.H. Interactive Atlas of Human Anatomy. 3rd ed. New Jersey, Icon Learning Systems, 2003, ISBN: 1-92900715-9, Plate #179 Author’s own Author’s own § bodyofthevertebraandthetransverseprocessarticulateswiththe transverseprocess § Thetubercleismadebymainlytheligamentsassociatedwiththe jointsbetweentheribsandthevertebra Ribs1-2,10-12=Atypicalribs • Theylookdifferenttoatypicalribduetodifferentmarkings • i.e.rib1(picture)–itisflatinthecoronalplaneunlikeotherribsthatareflat vertically.Therearesomegroovesforthesubclavianvesselsoverthetopofthefirst rib.Thereisascalenetubercleandthisisrelevantfortheattachmentofsomeofthe scalenemusclesintheneck. • [wedon’tneedtoknowthefeaturesofalltheatypicalribs–justknowthe relationshipofthestructuresaroundtheseribsbasedonthelumpsetc.] Sternum Clavicular notch Jugular notch Sternum • Thisiscommonlyknownasthebreastplate[check]andit Manubrium closestheanterioraspectofourribcage. Sternal angle Manubriosternal (of Louis) joint and • Itismadeof3differentprocesses: attachment of 2 Attachment for o Manubrium costal cartilage costal cartilages § Ithasajugularnotchwhichhassomehighly Body innervatedperiosteumandskin § Clavicularnotch–forthearticulationofthe Xiphoid process clavicles § Directlybelowtheclavicularnotchisthepointofarticulationforrib-1 • Rib2articulatesatthejunctionbetweenthemanubriumandthesternum= manubriosternaljoint o Inalateralview,wecanseeabumpthatisformedbytheangleofthe manubriumandthesternumatthisjoint o ThisisknownastheangleofLouisorthesternalangle o Ifweweretoputahorizontallineallthewaythroughthethoraxwewillget thistransverseplanethroughthesternalangleandthisiscalledtheplaneof Louis o Bodyofsternum o Xiphoidprocess–thisislargelycartilaginousuntilmuchlaterislifewhenitstartstoossifyand becomelesscartilaginous Transverse Superior Thoracic process articular facet Thoracicvertebra vertebra • Thoracicvertebrahasmanyfeaturessimilartoothervertebra Body buttheyhavesomeuniquefeatures Spinous process Spinous process Inferior articular facet Lamina Transverse Intervertebral process foramen Intervertebral Pedicle disc Articulationsforribs Vertebral Body Thoracic vertebrae permit canal • Thereisasuperiordemifacetforthearticulationwiththerib Articulations for ribsmainly rotation ofthesamenumberasthevertebra Costal facet Superior demifacet • Theinferiordemifacetarticulateswiththeribbelow (head of its own rib) Rib 3 • [note:Vertebraonehasasuperiorfacetnotademifacet Inferior demifacet andthefullribsitshere] Costal facet • Costovertebraljoint–thejointwheretheribandthe Costotransverse vertebrajoins joint • Costotransversejoint–thejointbetweenthetransverse Rib processofthevertebraandtherib Tubercle o Therearesomeligamentsreinforcingthisandthis Head occursattheCostalfacetofthetransverseprocess nd Author’s own Author’s own Costovertebral joint Author’s own Intercostal space Intercostalspace Intercostal Rib/Thoracic cage (muscle, nerves and vessels) • Intercostalspace–spacebetweeneachoftheribs space • Intercostalmuscles–musclesthatfillupthesespaces. Intercostal muscles Subcutaneous fat Superficial fascia Deep Fascia Skin Pectoralis Major sweat glands, fat, blood (superficial muscles) and lymphatic vessels, nerves, the mammary gland. Intercostalmuscles • Thereare3layersofintercostalmuscles–theyallruninthe Intercostal muscles samesortoforientation Internal • Themostsuperficiallayerofthemusclesiscalledthe intercostal External muscles intercostal externalintercostalmusclesandtheyrunantero-inferiorly (posteromuscles inferior) o Theyprojectallthewaythroughthespace (anteroDepress inferior) posteriorlyandanteriorlytheyformamembraneso Elevate therearenomusclefibresanteriorly External o Theexternalintercostalmuscleselevatetheribs intercostal o Theystopsomewhereatthecostochondraljunction membrane • Thesecondlayerofmusclesiscalledtheinternalintercostal musclesandtheyrunperpendiculartotheexternalintercostalmuscles–postero-inferiorly o Posteriorly,thesemusclesbreakdownandformamembranebutanteriorlywecanseeallthe musclesthroughtothesternum o Thereare2typesofmovementsheredependingonwhereintheintercostalspace § Ifitislateraltothecostochondraljunction–becausetheyhavetheoppositefibredirection toexternalintercostalmuscles,theinternalintercostalmuscleswilldepresstheribs(not elevate) § Iftheyaremedialtothecostochondraljunction– thentheywillelevatetheribs.Thisisduetothe shapeoftheribs(3Dstructureoftheribs) Innermost • Innermostintercostalmuscles–theytendtobebrokendownand intercostal muscle bepatchy (posteroo Posteriorlytheyareverydeficient–thereisnomembrane inferior) either Deficient posteriorly o Thedirectionofthesemusclefibresarethesameasthoseof theinternalintercostalmusclessotheybothmusthavethe samefunctions Innermost intercostal muscle Intercostal space Intercostalspace Internal intercostal muscle • Intercostalveins,arteriesandnervesareinbetween theinnermostintercostallayerandtheinternal External intercostal muscle Intercostal vein intercostalmusclelayer.Theyareshelteredhighin theintercostalspaceunderthecostalgroovepfthe Intercostal artery ribabove. Intercostal nerve o So,ifwewanttotheaspiratesomefluidin thepleurawewanttomakesurethatwe penetrateabovetheribbelowtoavoid goingclosetoanddamagingthis neurovascularbundle Costal groove of rib Netter, F.H. Interactive Atlas of Human Anatomy. 3rd ed. New Jersey, Icon Learning Systems, 2003, ISBN: 1-92900715-9, Plate #179 Eizenberg N, Briggs C, Barker P, Grkovic I. An@tomedia: Thorax module. Melbourne An@tomedia Publishing, 2001, ISBN: 0646 407 317 Eizenberg N, Briggs C, Barker P, Grkovic I. An@tomedia: Thorax module. Melbourne An@tomedia Publishing, 2001, ISBN: 0646 407 317 Author’s own Intercostal nerves Intercostalnerves • Thefigureisacoronalsection • Intercostalnervesareextensionsofthespinal segmentalnerveswhichcomesoutofthe intervertebralforaminaofthevertebral column • Asthespinalnerveleavestheintervertebral foraminaitalsogivesoffadorsalramusto supplytheskinandmusclesoverthevertebral column=erectorspinaemuscles • Asitcomesoutlaterally,theseintercostal nervesgiveoffmuscularbranchestoallthe intercostalmuscles(inthesamesegment)and thisisimportantastheyproducemovements oftheribsthatcontributetobreathing Rami Intercostal • Asitgoesthroughandrunsforward,itendsup communicantes nerve Innermost terminatingatsomecutaneousbranchesontheanterior intercostal Sympathetic muscle ganglion thoracicwallandalsosomelateralcutaneousbranches deficient posteriorly whichinnervatestheskinoverthelateralthoracicwall. o Eachofthesebranchessupplyastripofskinover thethoracicwallwhichisrelatedtothatspinal T4 teets segmentalwall.Thismakesiteasyforustodefine T1O thedermatomesinrelativetotheintercostal spaces.(itisasinglenervehere–thereareno plexusesandthereisnomixingetc.) Sympathetic trunk • Thereare12thoracicsegments.T4=stripovernipples andT10=stripoverbellybutton Intercostal Intercostalvessels vessels • Thereare2intercostalarteries–1posterior whichentersthespacefrombehindand1 anterioronethatentersthespacefromthe front. • Posteriorintercostalarteriesarejustsegmental branchesofthethoracicaorta • Anteriorintercostalarteriesarebranchesofthe internalthoracicarteries.Theinternalthoracic arteriesarebranchesofthesubclavianartery andtheydescendposteriorandlateraltothe sternumallthewaydownthesegmentsgiving anteriorintercostalarteriesintotheanterior aspectoftheintercostalspace. • Anteriorandposteriorintercostalnervesanastomosewitheachothersomewhereontheanteriorthoracic wall.Thisisimportantclinicallyasitprovidesanalternate Posterior intercostal Descending aorta artery routeforbloodtosomeoftheskinandmuscleinthis intercostalspace o Theinternalintercostalarteriesareoftenusedfor Internal thoracic bypassesofcoronaryarteryblockages. vessels • Thetransversusthoracismuscleisontheinsideoftheanterior thoracicwall.Itattachespartlytothesternumsoithasitsown name.Butithasthesamesortoffunctionsastheinnermost Anterior intercostalmuscles. intercostal artery Internal thoracic Transversus artery thoracis Moore K L. Clinically Oriented Anatomy. 2nd ed. Williams and Wilkins; 1985. ISBN 0683061321. Ch.1 Page 65 Netter, F.H. Interactive Atlas of Human Anatomy. 3rd ed. New Jersey, Icon Learning Systems, 2003, ISBN: 1929007-15-9, Plate #150 Netter, F.H. Interactive Atlas of Human Anatomy. 3rd ed. New Jersey, Icon Learning Systems, 2003, ISBN: 1-92900715-9, Plate #179 Moore K L. Clinically Oriented Anatomy. 2nd ed. Williams and Wilkins; 1985. ISBN 0683061321. Ch.1 Page 65 Netter, F.H. Interactive Atlas of Human Anatomy. 3rd ed. New Jersey, Icon Learning Systems, 2003, ISBN: 1-929007-15-9, Plate #176 Netter, F.H. Interactive Atlas of Human Anatomy. 3rd ed. New Jersey, Icon Learning Systems, 2003, ISBN: 1-92900715-9, Plate #179