1. Surface anatomy cardio respiratory system
IVC- approx 20cm runningdownon righthandside of vertebral column.
Sternal angle
Suprasternal/JugularNotch
Apex of the Heart- 5thintercostal inthe mid-clavicularline
SVC
2-3cm
RHSof midline
Underneathcostal
cartilage
AortaBifuricatesatL4- justbelowumbilicus
Trachearunsverticallydownmidlinefromlarynx (C3-C6) tothe sternal angle (secondcostal cartilage or
T4) where itdividesintothe leftandrightmainbronchi.
LeftUpperLobe
LeftLowerLobe
RightLowerLobe RightMiddle Lobe
LeftOblique Fissure
RightHorizontal Fissure
RightUpperLobe
The Thorax
-BonyCage formedby12 thoracic vertebrae.
-Upper7 pairsof ribs articulate anteriorlydirectlywiththe sternumviacostal cartilages.
-The 7thrib articulateswiththe sternumandxiphisternum
-The costal cartilage of ribs8, 9 and10 articulate withthe ribabove.I.e.10 with9, 9 with8, 8 with7.
-The 10th rib,costal cartilage andxiphisternumformthe lowercostal margin.
-the 11thand 12th ribsare knownas 'floatingribs'astheyhave no cartilage or bone anteriorly.
-The sternal angle (angle of louis) marksthe secondcostal cartilage'sjunctionwiththe sternum.
IntercostalSpaces
InnermostIntercostal Muscle
-The Skin,parietal pleuraandmuscle betweenribsare innervatedbythe intercostal nerves, whichcome off the corresponding thoracicvertebra.
-The internal thoracicartery(mammaryartery) onthe anteriorchestwall,branchingfromthe subclaviandescendsverticallyd ownwardslying1cmlaterallytothe
sternumbilaterally-thisandit'sbranchthe musculophrenicarterysupplythe anterioraspectof the chestandthe anteriorintercostal arteries.
-The posteriorintercostal arteriesare derivedmostlyfromthe descendingthoracicaorta.
-There are sitesof anastomosesbetweenthe anteriorandposteriorintercostal arteriesallowingforcollateral circulationin case of obstructiontobloodflowinthe
aortadistallytothe originof the subclavianarteries.
CardiacNotch
Rib
External Intercostal Muscle
Internal Intercostal Muscle
Vein
Intercostal Artery
Intercostal Nerve
Whendoingpleuralaspirationsora percutaneouspneumothorax decompression,insert
Needlesuperiortothe rib (Lowerhalf of intercostalspace abovetherib) toavoidneurovascular
bundle,whichif hit can causepainandneuritis or bleedinginto thepleural cavity(haemothorax).
Lungsand Pleura
Right
-Lungdividedintothree lobes,Upper,MiddleandLower.
-Lunghastwofissures,the oblique andhorizontal.
-The horizontal fissurefollowsthe 4thribaroundfromT4 to the articulationof the 4thrib and the sternum
-The oblique fissure startsposteriorlyatT2and anteriorlycomestothe 6th ribin the midclavicularline.
-Middle lobe onlyausclatedanteriorlyandlaterally.
-The Pleurasharesanapex withthe lungabout3cm above the medial partof the clavicle,thenposteriorlydescendingdirectly downtoT12.Anteriorly,the pleuradescendsbehindthe
SurfaceAnatomy of the Thorax
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2. -The Pleurasharesanapex withthe lungabout3cm above the medial partof the clavicle,thenposteriorlydescendingdirectly downtoT12.Anteriorly,the pleuradescendsbehindthe
sternoclavicularjointtowardsthe midlineatthe sternal angle.Fromthere itdescendsverticallydownwardstothe level of the sixthcostal cartilage.The pleurathenmakesitswaylaterally
crossingthe 8thrib inthe midclavicularline,the 10th ribin the mid-axillaryline andthentoT12 posteriorly.
Left
-TwoLobes,UpperandLower
-One,obliquefissure (T2-->5/6thrib)
-Aorta'imprint'onmediastinal surface
-CardiacNotch
-PleuraIdenticaltothe right,howeverfromthe sternal angle there isadeviationlaterallyforthe mediastinumandheart.O therwise almostidentical.
Pleura
-Consistsof acontinuouslayerof tissue,hasaparietal (outwards) surfaceandavisceral(nexttothe lung) surface.
-Thereis a potentialspacebetweenthe twosurfaces,withpleuralfluid secretedby mesothelialcells in the spaceto lubrica te andfacilitate movement.
-Pleuraconsistsof;anouterlayerof mesothelium,anarrowzoneof loose,fibrocollangenoustissue,anirregularelasticlay er, aninterstitial layer of loosefibrocollagenousstroma(supportive
framework) andanilldefinedinternalelastic layerwith shortelastic fibres.
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