Download the respiratory system

THERESPIRATORYSYSTEM
THERESPIRATORYSYSTEM
VISCERAOFTHORACICCAVITY
VISCERAOFTHORACICCAVITY
THERESPIRATORYSYSTEM
Thethoraciccavityisdividedintothreecompartments:
•  Rightandle9pulmonarycaviBes,bilateralcompartments
thatcontainthelungsandpleuraeandoccupythemajorityofthe
thoraciccavity.
•  AcentralmediasBnum,acompartmentinterveningbetweenand
completelyseparaFngthetwopulmonarycaviFes,whichcontains
essenFallyallotherthoracicstructures:theheart,thoracicpartsof
thegreatvessels,thoracicpartofthetrachea,esophagus,thymus,
andotherstructures(e.g.,lymphnodes).
PLEURAE
THERESPIRATORYSYSTEM
Eachlungisinvestedbyandenclosedinaserouspleuralsacthat
consistsoftwoconBnuousmembranes:thevisceralpleura,which
investsallsurfacesofthelungsformingtheirshinyoutersurface,and
theparietalpleura,whichlinesthepulmonarycaviFes
Thepleuralcavity-thepotenBalspacebetweenthelayers
ofpleura-containsacapillarylayerofserouspleuralfluid,which
lubricatesthepleuralsurfacesandallowsthelayersofpleuratoslide
smoothlyovereachotherduringrespiraFon.
Thevisceralpleura(pulmonarypleura)closelycoversthelungand
adherestoallitssurfaces,includingthosewithinthehorizontaland
obliquefissures.
ThevisceralpleuraisconFnuouswiththeparietalpleuraatthehilum
ofthelung,wherestructuresmakinguptherootofthelung(e.g.,
bronchusandpulmonaryvessels)enterandleavethelung.
PLEURAE
THERESPIRATORYSYSTEM
TheparietalpleuralinesthepulmonarycaviFes,therebyadheringto
thethoracicwall,mediasFnum,anddiaphragm.
Theparietalpleuraconsistsofthreeparts:
•  costal,
•  mediasFnal,
•  diaphragmaFc
•  andthecervicalpleura.
Thecostalpartoftheparietalpleura(costovertebralorcostalpleura)
coverstheinternalsurfacesofthethoracicwall.
Itisseparatedfromtheinternalsurfaceofthethoracicwall(sternum,
ribsandcostalcarFlages,intercostalmusclesandmembranes,and
sidesofthoracicvertebrae)byendothoracicfascia.
PLEURAE
THERESPIRATORYSYSTEM
ThemediasBnalpartoftheparietalpleura(mediasFnalpleura)covers
thelateralaspectsofthemediasFnum
ThediaphragmaBcpartoftheparietalpleura(diaphragmaFc
pleura)coversthesuperior(thoracic)surfaceofthediaphragmon
eachsideofthemediasFnum,exceptalongitscostala.achments(origins)
andwherethediaphragmisfusedtothepericardium
Athin,moreelasFclayerofendothoracicfascia,thephrenicopleural
fascia,connectsthediaphragmaFcpleurawiththemuscularfibersof
thediaphragm
Thecervicalpleuracoverstheapexofthelung-thepartofthelung
extendingsuperiorlythroughthesuperiorthoracicapertureintothe
rootoftheneck.
LUNGS
THERESPIRATORYSYSTEM
ThelungsarethevitalorgansofrespiraFon.TheirmainfuncFonisto
oxygenatethebloodbybringinginspiredairintocloserelaFonwith
thevenousbloodinthepulmonarycapillaries.
ThelungsareseparatedfromeachotherbythemediasBnum.
Eachlunghas:
•  apex
•  base
•  twoorthreelobes
•  threesurfaces
•  threeborders
LUNGS
THERESPIRATORYSYSTEM
Eachlunghas:
anAPEX,thebluntsuperiorendofthelungascendingabovethelevel
ofthe1stribintotherootoftheneck;theapexiscoveredbycervical
pleura.
ABASE,theconcaveinferiorsurfaceofthelung,oppositetheapex,
resFngonandaccommodaFngtheipsilateraldomeofthediaphragm
TWOORTHREELOBES,createdbyoneortwofissures.
THREESURFACES(costal,mediasFnal,anddiaphragmaFc).
THREEBORDERS(anterior,inferior,andposterior).
LUNGS
THERESPIRATORYSYSTEM
TherightlungislargerandheavierthantheleQ
Therightlungfeaturesrightobliqueandhorizontalfissuresthat
divideitintothreerightlobes:
•  superior
•  middle
•  inferior.
Thele9lunghasasingleleQobliquefissuredividingitintotwoleQ
lobes:
•  superior
•  inferior.
LUNGS
THERESPIRATORYSYSTEM
TheanteriorborderoftheleQlunghasadeepcardiacnotch
Themostinferiorandanteriorpartofthesuperiorlobeintoathin,
tongue-likeprocess,thelingulawhichextendsbelowthe
cardiacnotch
ThemediasBnalsurfaceofthelungisconcavebecauseitisrelatedto
themiddlemediasFnum
ThemediasBnalsurfaceincludesthehilum,whichreceivestheroot
ofthelung.
LUNGS
THERESPIRATORYSYSTEM
ThemediasBnumoftherightlung:
•  groovefortheesophagus
•  cardiacimpressionfortheheart
•  grooveforinferiorandsuperiorvenacava
•  grooveforazygosvein
ThemediasBnumofthele9lung:
•  cardiacimpressionfortheheart
•  grooveforthearchoftheaortaandthedescendingaorta
•  smallerareafortheesophagus
LUNGS
THERESPIRATORYSYSTEM
ThediaphragmaBcsurfaceofthelung,whichisalsoconcave,forms
thebaseofthelung,whichrestsonthedomeofthediaphragm.
Thebordersofthelung:
•  anterior
•  inferior
•  posterior
TheanteriorborderofthelungiswherethecostalandmediasFnal
surfacesmeetanteriorlyandoverlaptheheart.
TheinferiorborderofthelungcircumscribesthediaphragmaFc
surfaceofthelungandseparatesthissurfacefromthecostaland
mediasFnalsurfaces.
TheposteriorborderofthelungiswherethecostalandmediasFnal
surfacesmeetposteriorly
LUNGS
THERESPIRATORYSYSTEM
Therootsofthelungs–wherethelungsareaSachedtothe
mediasFnum.AshorttubularcollecFonofstructuresthattogether
aSachthelungtostructuresinthemediasFnum.
Therootsofthelungscontains:
•  bronchiandassociatedbronchialvessels,
•  pulmonaryarteries,
•  superiorandinferiorpulmonaryveins,
•  pulmonaryplexusesofnerves(sympatheFc,parasympatheFc),
•  lymphaFcvessels
Generally,thepulmonaryarteryissuperioratthehilum,
thepulmonaryveinsareinferior,andthebronchiaresomewhat
posteriorinposiFon.
THERIGHTLUNGS
THERESPIRATORYSYSTEM
Therightlunghasthreelobesandtwofissures.
Theobliquefissureseparatestheinferiorlobe(lowerlobe)fromthe
superiorlobeandthemiddlelobeoftherightlung.
Thehorizontalfissureseparatesthesuperiorlobe(upperlobe)from
themiddlelobe.
THELEFTLUNGS
THERESPIRATORYSYSTEM
Thele9lungissmallerthantherightlungandhastwolobes
separatedbyanobliquefissure.
TheobliquefissureoftheleQlungisslightlymoreobliquethanthe
correspondingfissureoftherightlung.
Inferiortotherootofthelung,thisconFnuitybetweenparietaland
visceralpleuraformsthepulmonaryligament,extendingbetweenthe
lungandthemediasFnum,immediatelyanteriortotheesophagus.
LUNGS
THERESPIRATORYSYSTEM
InthemediasFnum,thevagusnervespassimmediatelyposteriorto
therootsofthelungs,whilethephrenicnervespassimmediately
anteriortothem.
TRACHEOBRONCHIALTREE
THERESPIRATORYSYSTEM
TRACHEA
Isapproximately12cminlengthandhas16to20incompletehyaline
carBlaginousringsthatopenposteriorlytowardtheesophagusand
preventthetracheafromcollapsing.
BeginsattheinferiorborderofthecricoidcarBlage(C6)asa
conFnuaFonofthelarynx.
EndsbybifurcaBngintotherightandleQmainstembronchiatthe
levelofthesternalangle(discbetweenT4andT5).
TRACHEOBRONCHIALTREE
THERESPIRATORYSYSTEM
TRACHEA
Hasthecarina,adownwardandbackwardprojecFonofthelast
trachealcarFlage,whichliesatthelevelofthesternalangleandforms
akeel-likeridgeseparaFngtheopeningsoftherightandleQmain
bronchi.
Carinamaybedistorted,widenedposteriorly,andimmobileinthe
presenceofabronchogeniccarcinoma.
MaybecompressedbyanaorFcarchaneurysm,agoiter,orthyroid
tumors,causingdyspnea.
TRACHEOBRONCHIALTREE
THERESPIRATORYSYSTEM
RIGHTBRONCHUS
Therightmainbronchusiswider,shorter,andrunsmoreverBcally
thantheleQmainbronchusasitpassesdirectlytothehilumofthe
lung.
LEFTBRONCHUS
TheleQmainbronchuspassesinferolaterally,inferiortothearchof
theaortaandanteriortotheesophagusandthoracicaorta,toreach
thehilumofthelung.
TRACHEOBRONCHIALTREE
THERESPIRATORYSYSTEM
BRONCHI
Eachmainbronchusdividesintosecondarylobarbronchi:
•  twoontheleQ
•  threeontheright
EachlobarbronchusdividesintoseveralterFarysegmentalbronchi
thatsupplythebronchopulmonarysegments
TRACHEOBRONCHIALTREE
THERESPIRATORYSYSTEM
Thebronchopulmonarysegmentsare:
•  Thelargestsubdivisionsofalobe
•  Pyramidal-shapedsegmentsofthelung,withtheirapicesfacingthe
lungrootandtheirbasesatthepleuralsurface.
•  SeparatedfromadjacentsegmentsbyconnecFveFssuesepta.
•  SuppliedindependentlybyasegmentalbronchusandterFary
branchofthepulmonaryartery.
•  Namedaccordingtothesegmentalbronchisupplyingthem
•  Drainedbyintersegmentalpartsofthepulmonaryveins
•  Usually18–20innumber(10intherightlung;8–10intheleQlung,
dependingonthecombiningofsegments).
•  Surgicallyresectable
THERESPIRATORYSYSTEM
TRACHEOBRONCHIALTREE
LOBARBRONCHI
ê
•  segmentalbronchi
ê
•  terminalbronchioles
•  conducFngbronchioles
•  respiratorybronchioles
ê
•  pulmonaryalveolus
•  alveolarducts
•  alveolarsacs
Bronchioleslack
carFlagein
theirwalls
ConducFngbronchioles
transportairbutlack
glandsoralveoli.
Thepulmonaryalveolusisthebasicstructural
unitofgasexchangeinthelung.
VASCULATUREOFLUNGSANDPLEURAE
THERESPIRATORYSYSTEM
Eachlunghasapulmonaryarterysupplyingbloodtoitandtwo
pulmonaryveinsdrainingbloodfromit.
Therightandle9pulmonaryarteriesarisefromthepulmonary
trunkatthelevelofthesternalangle;theycarrylow-oxygen
(“venous”)bloodtothelungsforoxygenaFon.
Eachpulmonaryarterybecomespartoftherootofthecorresponding
lunganddividessecondarylobararteriesandsegmentalarteries.
Twopulmonaryveins,asuperiorandaninferiorpulmonary
veinoneachside,carryoxygen-rich(“arterial”)bloodfrom
correspondinglobesofeachlungtotheleQatriumoftheheart.
VASCULATUREOFLUNGSANDPLEURAE
THERESPIRATORYSYSTEM
BronchialarteriessupplybloodfornutriFonofthestructuresmaking
uptherootofthelungs,thesupporFngFssuesofthelungs,andthe
visceralpleura.
Thetwole9bronchialarteriesusuallyarisedirectlyfromthe
thoracicaorta.
Thesinglerightbronchialarterymayalsoarisedirectlyfromthe
aorta.
ThepulmonarylymphaBcplexusescommunicatefreely.
ThesuperficialsubpleurallymphaBcplexusliesdeeptothevisceral
pleuraanddrainsthelungparenchyma(Fssue)andvisceralpleura.
VASCULATUREOFLUNGSANDPLEURAE
THERESPIRATORYSYSTEM
LymphaFcvesselsfromthissuperficialplexusdrainintothe
bronchopulmonarylymphnodes.
ThedeepbronchopulmonarylymphaBcplexusislocatedinthe
submucosaofthebronchiandintheperibronchialconnecFveFssue.
LymphaFcvesselsfromthisdeepplexusdraininiFallyintotheintrinsic
pulmonarylymphnodes,locatedalongthelobarbronchi.
Lymphfromthetracheobronchiallymphnodespassestotheright
andleQbronchomediasFnallymphtrunks,themajorlymphconduits
drainingthethoracicviscera
Thesetrunksusuallyterminateoneachsideatthevenousangles
(juncFonsofthesubclavianandinternaljugularveins).
NERVESOFLUNGSANDPLEURAE
THERESPIRATORYSYSTEM
Thenervesofthelungsandvisceralpleuraarederivedfromthe
pulmonaryplexusesanteriorand(mainly)posteriortotheroots
ofthelungs
Thesenervenetworkscontain:
•  parasympatheFc
•  sympatheFc
•  visceralafferentfibers
TheparasympatheBcfibersconveyedtothepulmonaryplexusare
presynapFcfibersfromthevagusnerve(CNX).
ThesympatheBcfibersofthepulmonaryplexusesarepostsynapFc
fibers.
TheircellbodiesareintheparavertebralsympatheBcgangliaofthe
sympatheBctrunks
THERESPIRATORYSYSTEM
NERVESOFLUNGSANDPLEURAE
ThesympatheBcnervefibers
dilatetheluminaofthebronchi
andconstrictthepulmonary
vessels.
TheparasympatheBcfibers
constrictthelumina,dilatethe
pulmonaryvessels,andincrease
glandularsecreFon.
THERESPIRATORYSYSTEM
RESPIRATION
Isthevitalexchangeofoxygenandcarbondioxidethatoccursinthe
lungs.
Theair–bloodbarrierconsistsofalveolartypeIcells,basallamina,
andcapillaryendothelialcells.ThealveolartypeIIcellssecrete
surfactant.
INSPIRATION
THERESPIRATORYSYSTEM
Occurswhentheribsandsternum(orthoraciccage)areelevatedby
thefollowingmuscles:
•  thediaphragm
•  external,internal(interchondralpart),andinnermostintercostal
•  sternocleidomastoid
•  levatorcostarum
•  serratusanterior
•  scalenus
•  pectoralismajorandminor
•  serratusposteriorsuperiormuscles.
INSPIRATION
THERESPIRATORYSYSTEM
Involvesthefollowingprocesses:
1.ContracFonoftheDiaphragm
2.EnlargementofthePleuralCaviFesandLungs
3.ForcedInspiraBon
InvolvescontracFonoftheintercostalmusclesandelevaFonofthe
ribs(superolateralmovement),withthesternummovinganteriorly
likeabuckethandle.(Whenthehandleisraised,theconvexitymoves
laterally.)
Resultsinincreasedtransverseandanteroposteriordiametersofthe
thoraciccavity.
Theabdominalvolumeisdecreasedwithanincreasedabdominal
pressure.
EXPIRATION
THERESPIRATORYSYSTEM
Involvesthefollowingmuscles:themusclesoftheanteriorabdominal
wall,internalintercostal(costalpart)muscles,andserratusposterior
inferiormuscles.
Involvesthefollowingprocesses:
1.OverallProcess
2.ElasFcRecoiloftheLungs
3.ForcedExpiraFon
EXPIRATION
THERESPIRATORYSYSTEM
Involvesthefollowingprocesses:
1.OverallProcess
InvolvesrelaxaFonofthediaphragm,theinternalintercostalmuscles
(costalpart),andothermuscles;decreaseinthoracicvolume;and
increaseintheintrathoracicpressure.Theabdominalpressureis
decreased,andtheribsaredepressed.
EXPIRATION
THERESPIRATORYSYSTEM
Involvesthefollowingprocesses:
1.OverallProcess
2.ElasBcRecoiloftheLungs
ProducesasubatmosphericpressureinthepleuralcaviFes.Thus,
muchoftheairisexpelled.(QuietexpiraFonisapassiveprocess
causedbytheelasFcrecoilofthelungs,whereasquietinspiraFon
resultsfromcontracFonofthediaphragm.)
EXPIRATION
THERESPIRATORYSYSTEM
Involvesthefollowingprocesses:
1.OverallProcess
2.ElasFcRecoiloftheLungs
3.ForcedExpiraBon
RequirescontracFonoftheanteriorabdominalmusclesandthe
internalintercostals(costalpart).