Trachea and lungs - Doctor 2017 - JU Medicine€¦ · Lungs • organs of respiration and lie on...
Transcript of Trachea and lungs - Doctor 2017 - JU Medicine€¦ · Lungs • organs of respiration and lie on...
Tracheaandlungs
Trachea• Thetrachea isaflexibletubethatextendsfrom
vertebrallevelCVI(cricoidcartilage)inthelowernecktovertebrallevelTIV/V
• itbifurcatesintoarightandaleftmainbronchus(carina) atthelevelofsternalangle
• Thetracheaisheldopenby'C-shaped'cartilagerings(16-20)embeddedinitswall-
• theopenpartofthe'C'facingTheposteriorwallofthetracheaiscomposedmainlyofsmoothmuscle(trachealis)andconnectivetissue.
• Inadultsthetracheaisabout4½in.(11.25cm)longand1in.(2.5cm)indiameter
- Thetracheawidensandlengthensslightlywitheachinspiration,returningtoitsrestingsizewitheachexpiration.
RelationsofTracheaAnteriorlly• Aorticarch• Thymus• thyroid• Originofbrachiocephalicartery• ManubriumsterniLeft• Archofaorta• Lt.subclavianart.• LT.commoncarotidart.• Lt.Phrenicn.• Lt.Vagusn.• Lt.mainbronchusRight- Azygousarch- Brachiocephalicartery- Rt.Vagus- Rt.Phrenic- Rt.mainbronchusPost.- Esophagus- Thoracicduct- leftrecurrentlaryngealnerve
Trachea• carina isacartilaginousridgewithinthe
trachea thatrunsanteroposteriorlybetweenthetwoprimarybronchi atthesiteofthetrachealbifurcation(T4-T5).
• Themucousmembraneofthecarinaisthemostsensitiveareaofthetracheaandlarynxfortriggeringacoughreflex.
• Indeepinspirationitdescendstothelevelof6th thoracicvertebra
Tracheotomyandintubations• Usedtoreestablishairflowpastatrachealobstruction.
• Iftheobstructionissuperiortothelarynxatracheotomymaybeperformed
• Alongitudinalincisionbelowthecricoidcartilage
• Thepatientcanthebreaththroughametalorplastictube.
• inintubationthetubeisinsertedthroughthemouthornoseandpushasideanyflexibleobstruction
• Anymucouscloggingcanbesuctionedthroughthetube
Bronchi
• Eachmainbronchusenterstherootofalungandpassesthroughthehilumintothelungitself.
• Therightmainbronchus iswiderandtakesamoreverticalcourseandisabout1in.(2.5cm)
• principalbronchusgivesoffthesuperiorlobarbronchus.Onenteringthehilum,itdividesintoamiddleandaninferiorlobarbronchus.
• theleftmainbronchusisnarrower,longer,andmorehorizontalthantherightandisabout2in.(5cm)long
• passestotheleftbelowthearchoftheaortaandinfrontoftheesophagus
• theprincipalbronchusdividesintoasuperiorandaninferiorlobarbronchus.
• Therefore,inhaledforeignbodiestendtolodgemorefrequentlyontherightsidethanontheleft.
Bronchialtree• Themainbronchusdivideswithinthelung
intolobarbronchi (secondarybronchi),
• eachofwhichsuppliesalobe.
• Ontherightside,thelobarbronchustothesuperiorlobeoriginateswithintherootofthelung.
• Thelobarbronchifurtherdivideintosegmentalbronchi (tertiarybronchi),whichsupplybronchopulmonarysegments
Bronchialtree• bronchopulmonarysegment furtherdivideintoterminalbronchioles&theseintorespiratorybronchioleswhichendinthepulmonaryunit.
- Pulmonaryunitconsistofalveolarducts,atria
airsacspulmonaryalveoli.
• Thewallsofthebronchiareheldopenbydiscontinuouselongatedplatesofcartilage,butthesearenotpresentinbronchioles.
Bronchialtree
Bronchialtree
Bronchopulmonarysegments• Abronchopulmonarysegment isthearea
oflungsuppliedbyasegmentalbronchusanditsaccompanyingpulmonaryarterybranch
• Itisasubdivisionofalunglobe.
• Itispyramidshaped,withitsapextowardthelungroot.
• Itissurroundedbyconnectivetissue.
• Ithasasegmentalbronchus,asegmentalartery,lymphvessels,andautonomicnerves.
• Thesegmentalveinliesintheconnectivetissuebetweenadjacentbronchopulmonarysegments.
• Becauseitisastructuralunit,adiseasedsegmentcanberemovedsurgically.
BronchopulmonarysegmentsRt.Lung10segmentsUpperlobeApicalposteriorAnt
MiddlelobeMedialLateral
BasallobeApical(apicobasal)AntMedLatPost
BronchopulmonarysegmentsLt.lung10segments
UpperlobeApicalposteriorAntsup.Lingualinf.lingual
BasallobeApical(apicobasal)AntMedLatPost
Bronchopulmonarysegments
Bronchopulmonarysegments
Beforebirth:- Rt.Lung10segments
- Lt.lung8segmentsApicpoposteriorAnteromedial
Clinicalimportanceofpulmonarysegments• Infections• Nobarrier• Surgery• Posturaldrainage• Bronchoscopy
Lungs
Lungs• organsofrespirationandlieoneithersideofthe
mediastinum
• surroundedbytherightandleftpleuralcavities
Spongy,grey,darklateron.
• 600-800gm,90%air&10%tissue
• Thepulmonaryarteriesdeliverdeoxygenatedbloodtothelungsfromtherightventricleoftheheart.
• Oxygenatedbloodreturnstotheleftatriumviathepulmonaryveins.
• Therightlungisnormallyalittlelargerthantheleftlungbecausethemiddlemediastinum,containingtheheart,bulgesmoretotheleftthantotheright.
Leftlungisnarrower-Rightlungisshorter,morevertical
Lungs• Eachlunghasahalf-coneshape
• base,apex,twosurfacesandthreeborders
• Thebase sitsonthediaphragm.
• Theapex projectsaboveribIandintotherootoftheneck.
1inchabovethemedial1/3rd oftheclavicleandisCoveredbysuprapleuralmembran.
• costalsurface liesimmediatelyadjacenttotheribsandintercostalspaces.
• Themediastinalsurface liesagainstthemediastinumanteriorlyandthevertebralcolumnposteriorly
• containsthecomma-shapedhilumofthelungthroughwhichstructuresenterandleave.
Lungs• inferiorborder ofthelungissharpandseparatesthebasefromthecostalsurface.
• Theanterior andposteriorborders separatethecostalsurfacefromthemedialsurface.
• theanteriorandinferiorborders,aresharp,
• theposteriorborderissmoothandrounded
Surfaceanatomyofthelung
• Atend-expiration• 6th rib– midclavicular• 8th rib– midaxillary• 10th T.vertebra_
Posteriorly- apexisat1stTh vertebra
• PosteriorborderExtendfrom7th Cvert.tothe10th Tvert.- lies4cmfromthemidline
Inferiorborder• Ascendanddescendbetween9th &12th rib
Rootandhilum• Theroot ofeachlungisashorttubularcollection
ofstructuresthattogetherattachthelungtostructuresinthemediastinum
• coveredbyasleeveofmediastinalpleurathatreflectsontothesurfaceofthelungasvisceralpleura
• Athinblade-likefoldofpleuraprojectsinferiorlyfromtherootofthelung.Thisstructureisthepulmonaryligament
• pulmonaryligament stabilizethepositionoftheinferiorlobeandmayalsoaccommodatethedown-and-uptranslocationofstructuresintherootduringbreathing
• thevagusnervespassimmediatelyposteriortotherootsofthelungs,whilethephrenicnervespassimmediatelyanteriortothem.
Rootandhilum
• Withineachrootandlocatedinthehilumare:• pulmonaryartery;• twopulmonaryveins;• amainbronchus;• bronchialvessels;• nerves;• lymphatics.
Rootandhilum• thepulmonaryarteryissuperioratthehilum,
• thepulmonaryveinsareinferior,andthebronchiaresomewhatposteriorinposition.
• Ontherightside,thelobarbronchustothesuperiorlobebranchesfromthemainbronchusintheroot,
• ontheleftitbrancheswithinthelungitself,andissuperiortothepulmonaryartery
Rightlung• Therightlung hasthreelobesandtwofissures
• Normally,thelobesarefreelymovableagainsteachotherbecausetheyareseparated,almosttothehilum,byinvaginationsofvisceralpleura.
• Theseinvaginationsformthefissures:• theobliquefissure separatestheinferiorlobe (lowerlobe) fromthesuperiorlobeandthemiddlelobeoftherightlung;
• thehorizontalfissure separatesthesuperiorlobe(upperlobe) fromthemiddlelobe.
Rightlung• Theapproximatepositionoftheobliquefissureonapatient,inquietrespiration,
• beginsroughlyatthespinousprocessofvertebraT4 levelofthespine,crossesthefifthinterspacelaterally,andthenfollowsthecontourofribVI anteriorly
Rightlung• Thehorizontalfissurefollowsthefourthintercostal spacefromthesternumuntilitmeetstheobliquefissureasitcrossesribV.
• Theorientationsoftheobliqueandhorizontalfissuresdeterminewherecliniciansshouldlistenforlungsoundsfromeachlobe.
• Whenlisteningtolungsoundsfromeachofthelobes,itisimportanttopositionthestethoscopeonthoseareasofthethoracicwallrelatedtotheunderlyingpositionsofthelobes
Rightlung
• Themedialsurfaceoftherightlungliesadjacenttoanumberofimportantstructurestheheart,• inferiorvenacava,• superiorvenacava,• azygosvein,• esophagus.
Rightlung
• Therightsubclavianarteryandveinarchoverandarerelatedtothesuperiorlobeoftherightlungastheypassoverthedomeofcervicalpleuraandintotheaxilla.
Leftlung• Theleftlung issmallerthantherightlung
andhastwolobesseparatedbyanobliquefissure
• obliquefissure oftheleftlungisslightlymoreobliquethanthecorrespondingfissureoftherightlung
• Duringquietrespiration,theapproximatepositionoftheleftobliquefissurecanbemarkedbylineonthethoracicwall
• beginsbetweenthespinousprocessesofvertebraeT3andT4,crossesthefifthinterspace laterally,andfollowsthecontourofribVI anteriorly
• Aswiththerightlung,theorientationoftheobliquefissuredetermineswheretolistenforlungsoundsfromeachlobe.
Leftlung
• Theinferiorportionofthemedialsurfaceoftheleftlung,isnotchedbecauseoftheheart'sprojection intotheleftpleuralcavityfromthemiddlemediastinum
• Ontheanteriorsurfaceofthelowerpartofthesuperiorlobeatongue-likeextension(thelingulaofleftlung)projectsovertheheartbulge.
Leftlung
• Themedialsurfaceoftheleftlungliesadjacenttoanumberofimportantstructuresthe
• heart,• aorticarch,• thoracicaorta,• esophagus
RIGHT LUNG
3 LobesUpper Middle and Lower
2 FissuresOblique & Horizontal
Segments
Secondary Lobules
LEFT LUNG
2 LobesUpper and Lower
1 FissureOblique
Segments
Secondary Lobules
Rightside
Leftside
Pulmonaryarteries• Therightandleftpulmonaryarteries
originatefromthepulmonarytrunk andcarrydeoxygenatedbloodtothelungsfromtherightventricleoftheheart
• ThebifurcationofthepulmonarytrunkoccurstotheleftofthemidlinejustinferiortovertebrallevelT4,andanteroinferiorlytotheleftofthebifurcationofthetrachea.
• Therightpulmonaryartery islongerthantheleftandpasseshorizontallyacrossthemediastinumItpasses:
• anteriorlyandslightlyinferiorlytothetrachealbifurcationandanteriorlytotherightmainbronchus;
• posteriorlytotheascendingaorta,superiorvenacava,andupperrightpulmonaryvein.
Pulmonaryarteries• Therightpulmonaryarteryenterstherootofthelungandgivesoffalargebranchtothesuperiorlobeofthelung.
• Themainvesselcontinuesthroughthehilumofthelung,givesoffasecond(recurrent)branchtothesuperiorlobe,andthendividestosupplythemiddleandinferiorlobes
• Theleftpulmonaryartery isshorterthantherightandliesanteriortothedescendingaortaandposteriortothesuperiorpulmonaryvein
• Itpassesthroughtherootandhilumandbrancheswithinthelung.
Pulmonaryveins
• Oneachsideasuperiorpulmonaryvein andaninferiorpulmonaryvein carryoxygenatedbloodfromthelungsbacktotheheart
• Theveinsbeginatthehilumofthelung,passthroughtherootofthelung,andimmediatelydrainintotheleftatrium.
Bronchialarteriesandveins• constitutethe'nutritive'vascularsystemofthe
pulmonarytissues(bronchialwallsandglands,wallsoflargevessels,andvisceralpleura).
• Theyinterconnectwithinthelungwithbranchesofthepulmonaryarteriesandveins.
• Thebronchialarteriesoriginatefromthethoracicaortaoroneofitsbranches:
• asinglerightbronchialartery normallyarisesfromthethirdposteriorintercostalartery
• twoleftbronchialarteries arisedirectlyfromtheanteriorsurfaceofthethoracicaorta
• thesuperiorleftbronchialartery arisesatvertebrallevelT5,andtheinferioroneinferiortotheleftbronchus.
• Thebronchialarteriesrunontheposteriorsurfacesofthebronchiandramifyinthelungstosupplypulmonarytissues.
bronchialveins• bronchialveins draininto:
• eitherthepulmonaryveinsortheleftatrium;
• intotheazygosveinontherightorintothesuperiorintercostalveinorhemiazygosveinontheleft.
Innervation• Thevisceralpleuraandotherstructuresofthe
lungaresuppliedbyvisceralafferentsandefferents distributedthroughtheanteriorpulmonaryplexusandposteriorpulmonaryplexus
• Theseinterconnectedplexuseslieanteriorlyandposteriorlytothetrachealbifurcation andmainbronchi.
• Theanteriorplexusismuchsmallerthantheposteriorplexus.
• Branchesoftheseplexuses,whichultimatelyoriginatefromthesympathetictrunksandvagusnerves,aredistributedalongbranchesoftheairwayandvessels
• Visceralefferents from:
• thevagusnervesconstrictthebronchioles;
• thesympatheticsystemdilatethebronchioles.
Lymphaticdrainage• Superficial,orsubpleural,anddeep
lymphaticsofthelungdrainintolymphnodescalledtracheobronchialnodesaroundtherootsoflobarandmainbronchiandalongthesidesofthetrachea
• Asagroup,theselymphnodesextendfromwithinthelung,throughthehilumandroot,andintotheposteriormediastinum
• Efferentvesselsfromthesenodespasssuperiorlyalongthetracheatounitewithsimilarvesselsfromparasternal nodesandbrachiocephalic nodes,toformtherightandleftbronchomediastinaltrunks
• Thesetrunksdraindirectlyintodeepveinsatthebaseoftheneck,ormaydrainintotherightlymphatictrunkorthoracicduct.
Pleura
Pleura• Eachpleuralcavityislinedbyasinglelayerofflat
cells,mesothelium,andanassociatedlayerofsupportingconnectivetissue;together,theyformthepleura
• Thepleura isdividedintotwomajortypes,basedonlocation:
• pleuraassociatedwiththewallsofapleuralcavityisparietalpleura;
• visceralpleura whichadherestoandcoversthelung.
• Eachpleuralcavityisthepotentialspaceenclosedbetweenthevisceralandparietalpleurae.Theynormallycontainonlyaverythinlayerofserousfluid
• Asaresult,thesurfaceofthelung,whichiscoveredbyvisceralpleura,directlyopposesandfreelyslidesovertheparietalpleuraattachedtothewall.
Pleura
• Function:• 1- protection• 2- Producesfluidthatallowsforlubrication
- Failuretofunctionresultsindifficultpainfulbreathing
- Thepleuralcavityisasitefor—pneumothorax,pleuraleffusion,Empyema&haemothorax.
Pleura• Thenamesgiventotheparietalpleuracorrespondtothepartsofthewallwithwhichtheyareassociated
• pleurarelatedtotheribsandintercostalspacesistermedthecostalpart;
• pleuracoveringthediaphragmisthediaphragmaticpart;
• pleuracoveringthemediastinumisthemediastinalpart;
• thedome-shapedlayerofparietalpleuraliningthecervicalextensioniscervicalpleura (domeofpleura orpleuralcupola)andiscoveredbysuprapleuralmembrane(sibson’sfascia).
Pleura• intheregionofvertebraeTVtoTVII,themediastinalpleurareflects,formstherootofthelung
• Therootjoinsthemedialsurfaceofthelungatthehilum,andthemediastinalpleurabecomescontinuouswiththevisceralpleura.
Peripheralreflections• Theperipheralreflectionsofparietalpleura
marktheextentofthepleuralcavities
• Superiorly,thepleuralcavitycanprojectasmuchas3-4cmabovethefirstcostalcartilage,butdoesnotextendabovetheneckofribI.
• ThislimitationiscausedbytheinferiorslopeofribItoitsarticulationwiththemanubrium.
• Anteriorly,thepleuralcavitiesapproacheachotherposteriortotheupperpartofthesternum.
• posteriortothelowerpartofthesternum,theparietalpleuradoesnotcomeasclosetothemidlineontheleftsideasitdoesontherightbecausetheheartbulgestotheleft.
Peripheralreflections
• Inferiorly,thecostalpleurareflectsontothediaphragmabovethecostalmargin.Inthemidclavicular line,thepleuralcavityextendsinferiorlytoapproximatelyribVIII.
• Inthemidaxillary line,itextendstoribX.
• Fromthispoint,theinferiormargincoursessomewhathorizontally,crossingribsXIandXIItoreachvertebraTXII.
• Fromthemidclavicular linetothevertebralcolumn,theinferiorboundaryofthepleuracanbeapproximatedbyalinethatrunsbetweentheribVIII,ribX,andvertebraTXII.
Suprapleuralmembrane
• Afibroussheathattachedto:• Laterally:medialborderof1st ribandcostalcartilage
• Medially:blendwithfasciainvestingthestructurethatpassfromthoraxtoneck
• Apex:tothetipofthetransverseprocessofthe7th cervicalvertebra
• Action:protectthecervicalpleuraandlunga
• Alsoresistchangesintheintrathoracicpressureduringrespiratorymovements
Visceralpleura
• Visceralpleuraiscontinuouswithparietalpleuraatthehilumofeachlungwherestructuresenterandleavetheorgan
• Thevisceralpleuraisfirmlyattachedtothesurfaceofthelung,includingbothopposedsurfacesofthefissuresthatdividethelungsintolobes
Pleuralrecesses• Thelungsdonotcompletelyfilltheanteriororposteriorinferiorregionsofthepleuralcavities
• Thisresultsinrecessesinwhichtwolayersofparietalpleurabecomeopposed.
• Expansionofthelungsintothesespacesusuallyoccursonlyduringforcedinspiration
• therecessesalsoprovidepotentialspacesinwhichfluidscancollectandfromwhichfluidscanbeaspirated.
Pleuralrecesses• Costomediastinalrecessesoccursoneachsidewherecostalpleuraisopposedtomediastinalpleura.Thelargestisontheleftsideintheregionoverlyingtheheart.
• Thelargestandclinicallymostimportantrecessesarethecostodiaphragmaticrecesses,
• whichoccurineachpleuralcavitybetweenthecostalpleuraanddiaphragmaticpleura
• Thecostodiaphragmaticrecessesaretheregionsbetweentheinferiormarginofthelungsandinferiormarginofthepleuralcavities
Pleuralrecesses• Theyaredeepestafterforcedexpirationand
shallowestafterforcedinspiration.
• Duringquietrespiration,theinferiormarginofthe lungcrossesribVIinthemidclavicularline,ribVIIIinthemidaxillaryline,andthencoursessomewhathorizontallytoreachthevertebralcolumnatvertebrallevelT10
• theinferiormarginofthe lungcanbeapproximatedbyalinerunningbetweenribVI,ribVIII,andvertebraT10.
• TheinferiormarginofthepleuralcavityatthesamepointsisribVIII,ribX,andvertebraT12.Thecostodiaphragmaticrecessistheregionbetweenthetwomargins.
Therelationshipsofthepleuralreflectionsandthelobesofthelung
atthemidclavicularline,therecessisbetweenribspaces6and8,• atthemidaxillarylinebetween8and10• attheparavertebrallinebetween10and12.
Costodiaphragmaticrecess
• 1”(1inch) inthemidclavicularline
• 2”inthescapularlinepost
• 3”inthemidaxillaryline
Clinicalnote
• Aspirationoffluid(pneumothorax)fromthepleuralcavitybyputtinganeedlethroughthe7thintercostalspaceinthemidclavicularlineorinanyotherrecesses
• Theneedleisputinthelowerborderofthespace.
Pleuraleffusion
- Pleuralspacenormallycontain5- 10mlofclearfluid
- Absorbednormallybyvisceralpleurabyhydrostaticandosmoticpressure
- Pleuraleffusion:isaccumulationofexcessfluidwithinthepleuralcavity,pleuralfluidincreasemorethan300(ml)incostodiaphragmaticrecess
- Maincauses1- Infection2- Injury
ClinicalManifestations• Decreaseinlungexpansion• Decreasebreathsound• InPercussionà Dullness• Pain• Cough
NervesupplyofthepleuraParietalpleura:- Itissensitiveto
painTempTouch&pressure
1- Intercostalnervesà Costalpleura(segmentaly)
2- PhrenicnerveàMediastinalpleura+diaphragmaticpleura
3- lower6intercostalà peripheralpleuraVisceralpleura- Sensitivetostretch- Insensitivetopain,temportouch- Suppliedbypulmonaryplexus&autonomic.N.S
ArterialSupplyofthePleura
• Thearterialsupplyoftheparietalpleura isfromthearteriesthatsupplythethoracicwall
Intercostalarteries(ant&post)InternalthoracicMusculophrenicarteries.
• Thearterialsupplyofthevisceralpleura isfromthe-Bronchialarteries,whicharebranchesofthethoracicaorta.
Veinsdrainintoazygos &internalthoracicveins.
Lymphaticdrainageofpleura
parietalpleuraMediastinalpleuraby
1- mediastinalnodes2- Tracheobronchialnodes3- Intercostalnodes
Diaphragmaticpleura1- Parasternalnodes2- Post.mediastinalnodes
• Pulmonarypleura(visceral):alongbronchialarteries→bronchopulmonarynodes
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