THORACIC WALL Salvador Dali - Anthropomorphic Chest of Drawers, 1936 Kaan Yücel M.D., Ph.D. 14.October.2011Friday
Thethoraxis thepart of the body betweentheneckand abdomen. Posterior surface:: 12 thoracic vertebrae& posterior parts of the ribsAnterior surface:Sternum& costal cartilagesLateral surfaces:Ribs, separated from each other by the intercostal spaces
Thefloor of thethoraciccavityis deeplyinvaginatedinferiorlybyviscera of theabdominalcavity.
The thorax includes the primary organs of the respiratoryand cardiovascularsystems. The thoracic cavity 3 major spaces Mediastinum – centralcompartmentRight& left pulmonary cavities The majority of the thoracic cavitylungs Heart& structures involved in conducting the air and blood to and from the lungs +Esophagus
Thoracic Wall • The true thoracic wall includes: • The thoracic cage and the muscles that extend between the ribs as well as the skin, subcutaneous tissue, muscles, and fascia covering its anterolateral aspect. • The mammary glands of the breasts lie within the subcutaneous tissue of the thoracic wall.
Thedomedshape of thethoraciccageprovidesitscomponentsenablingto: • Protectvitalthoracicandabdominalorgans (mostairorfluidfilled) fromexternalforces. • Resistthenegative (sub-atmospheric) internalpressuresgeneratedbytheelasticrecoil of thelungsandinspiratorymovements. • Provideattachmentforandsupporttheweight of theupperlimbs. • Providetheanchoringattachment (origin) of many of themusclesthatmoveandmaintaintheposition of theupperlimbsrelativetothetrunk, as well as providetheattachmentsformuscles of the abdomen, neck, back, andrespiration. • Thethorax is one of themostdynamicregions of the body.
Skeleton of Thoracic Wall • 12 pairs of ribsandassociatedcostalcartilages • 12 thoracicvertebraeandtheintervertebral (IV) discs • Sternum • Ribs & costalcartilageslargestpart of thethoraciccage • Bothareidentifiednumerically, fromthemostsuperior (1st riborcostalcartilage) tothemostinferior (12th).
ThoracicVertebrae Characteristic features of thoracic vertebrae • Bodies, vertebral arches, 7 processes for muscular & articular connections Costal facets (demifacets) on the vertebral bodies, inferior & superior pairs, articulation w/ theheads of theribs Costal facets on the transverse processes articulation w/ thetubercles of theribs, except inferior 2 or 3 Th vertebrae • Spinous processes
Ribs & IntercostalSpaces Ribs (L. costae) 12 pairs of curved, flat bones Form most of the thoracic cage
3 types of ribs True (vertebrocostal) ribs Carticalages’ directconnection w/ thesternum False (vertebrochondral) ribsIndirectconnectionwiththesternum Cartilages’ connection w/ thesuperiorrib Floating (vertebral, free ribs) No connection w/ thesternum VIIII- X XI-XIIII
Typical ribs (3rd to 9th) • HeadHas twoarticularfacets • articulatewithnumericallycorrespondingvertebra • articulatewithonesuperiorvertebra • NeckConnectstheheadwiththe body at thetubercle • TubercleBetweentheshaftandtheneck. Has an articularfacetforarticulatingwiththetransverseprocess of thecorrespondingvertebra. • Body Concaveinternalsurface has thecostalgroovefortheintercostalnerveandvessels. Bearstheangle.
Atypicalribs1st, 2nd, and 10th-12th ribsaredissimilar. • Costalcartilagesprolongtheribsanteriorlyandcontributetotheelasticity of thethoracicwall, providing a flexibleattachmentfortheiranteriorends.
Intercostalspacesseparatetheribsandtheircostalcartilagesfromoneanother. Namedaccordingtotheribformingthesuperiorborder of thespace The 4th intercostalspaceliesbetweenribs 4 and5. 11 intercostalspacesand 11 intercostalnerves
STERNUM G. sternon, chest Has threeparts: 1. Manubrium 2. Body 3. Xiphoidprocess Jugularnotch @ sup. margin of themanubrium Level of T2 vertebra Clavicularnotch
Sternal angle is formedbythejunction of themanubriumwiththe body of thesternum. Lies at the level of 2nd costal cartilage anteriorly Xiphoid process is an important for the inferior border of the heart and upper border of the liver.
ThoracicApertures • Whilethethoraciccageprovides a completewallperipherally, it is opensuperiorlyandinferiorly. • Thesuperioropening is a passagewaythatallowscommunicationwiththeneckandupperlimbs. • Thelargerinferioropeningprovidesthe ring-likeorigin of thediaphragm, whichcompletelyoccludestheopening.
Structuresthatpassbetweenthethoraciccavityandtheneckthroughthesuperiorthoracicaperture:Structuresthatpassbetweenthethoraciccavityandtheneckthroughthesuperiorthoracicaperture: • Trachea • Esophagus • Nerves, andvesselsthatsupplyanddrainthehead, neck, andupperlimbs.
Joints of Thoracic Wall Costa transverse joints Sterno costal joint Costachondralisjoint IntercondralJoints Sternal JointsManubrium, body, xiphoid process of the sternum.
Muscles of Thoracic Wall • Somemusclesattachedtoand/orcoveringthethoraciccageareprimarilyinvolved in servingotherregions. • Several(axioappendicular) musclesextendfromthethoraciccage (axialskeleton) tobones of theupperlimb (appendicularskeleton). • Muscles, such as sternocleidomasteoidmuscle, abdominalmuscles, pectoralmuscles, function as accesorymuscles of respiratonandwork in forcedrespiration; whenthepersonneedstobreathe in andoutmorethanusual; 100 metersprinters, patientswithrespiratoryproblems.
Musclesof thethoracicwall • Serratusposteriormuscles • Levatorcostarummuscles • Intercostalmuscles(External, internalandinnermost) • Subcostalmuscle • Transversethoracicmuscle • Thesemuscleseitherelevateordepresstheribshelpingtoincresethevolume of thethoraciccavity.
Thediaphragm is a sharedwall (actuallyfloor/ceiling) separatingthethoraxand abdomen. Although it has functionsrelatedtobothcompartments of thetrunk, itsmostimportant (vital) function is serving as theprimarymuscle of inspiration.
Vasculature of Thoracic Wall In general, the pattern of vascular distribution in the thoracic wall reflects the structure of the thoracic cage—that is, it runs in the intercostal spaces, parallel to the ribs.
Arteries of Thoracic Wall • Branches of the • Thoracic aorta • Subclavianartery • Axillaryartery
Arteries of Thoracic Wall Theintercostalarteriescoursethroughthethoracicwallbetweentheribs.
Veins of Thoracic Wall Intercostalveinsaccompanytheintercostalarteries & nervesMostsuperior in thecostalgrooves 11 posteriorintercostalveins + 1 subcostalvein on eachside. Posteriorintercostalveinsanastomoseanteriorintercostalveins Mostposteriorintercostalveins (4-11) end in theazygos/hemiazygosvenoussystem SVC.
Nerves of Thoracic Wall The 12 pairs of thoracicspinalnervessupplythethoracicwall. As soon as theyleavethe IV foramina in whichtheyareformed, themixedthoracicspinalnervesdivideintoanteriorandposterior (primary) rami orbranches. Theanterior rami of nerves T1-T11 form theintercostalnervesthatrunalongtheextent of theintercostalspaces.
Nerves of Thoracic Wall • Theintercostalnervespasstoandthencontinuetocourse in orjustinferiortothecostalgrooves, runninginferiortotheintercostalarteries (which, in turn, runinferiortotheintercostalveins). • Theneurovascularbundles (andespeciallythevessels) arethusshelteredbytheinferiormargins of theoverlyingrib.
Dermatomes The skin area supplied by a segment of the spinal cor.d The skin area supplied by a segment of the spinal cord. Sternalangle Nipple Xiphoidprocess Costalarch Umbiculus Midpoint between umbilicus and symphysis pubis
Breasts • Thebreasts (L. mammae) arethemostprominentsuperficialstructures in theanteriorthoracicwall, especially in women. • Accessorytoreproduction in women • Rudimentaryandfunctionless in men, consisting of only a fewsmallductsorepithelialcords. • Mammaryglandsliesuperficialtothepectoralismajormuscle • Theanteriorpart is calledthenippleand • it is surroundedby a circularpigmentedarea of skin, calledtheareola
Lymphaticdrainage • Axillarylymphnodes , • Parasternallymphnodes • Abdominallymphnodes
Arterialsupply of thebreast Medialmammarybranches Lateralmammarybranches, lateralthoracic & thoracoacromialarteries3. Posteriorintercostalarteries2nd-4th
Venousdrainage of thebreast Mainlytotheaxillaryvein, sometotheinternalthoracicvein
Nerves of the breast Anteriorandlateralcutaneousbranches of the 4th-6th intercostalnerves
MEDIASTINUM • Thethoraciccavity is dividedintothreemajorspaces: • Thecentralcompartmentormediastinumthathousesthethoracicvisceraexceptforthelungsand, on eachside • Therightandleftpulmonarycavitieshousingthelungs.
Themediastinum (Mod. L. middleseptum, L, mediastinus,midway), occupiedbythemass of tissuebetweenthetwopulmonarycavities, is thecentralcompartment of thethoraciccavity. • Itis covered on eachsidebymediastinalpleuraandcontainsallthethoracicvisceraandstructuresexceptthelungs.
Mediastinum SuperiortoInferior Fromsuperiorthoracicaperturetothediaphragm AnteriortoPosterior Fromsternum & costalcartilagestothebodiesof thethoracicvertebrae