December, 1960 P H Y S I O T H E R A P Y paqe 3 Anatomy of the Thorax B y D r. L. M . J O N C K , B .C h .D ., M .Sc., D .S c. S e n io r L ec tu re r o f A n a to m y , P re to ria U niversity. A L ecture given to D elegates a nd M e m b ers o f the S o u th A fric a n S o c ie ty o f P hysiotherapy on the fir s t day o f the “ Chest Course” , which was h eld a t the P retoria H o sp ita l P hysiotherapy S chool on M a y 27th and 28th, 1960. T he a n a to m y o f th e th o ra x c a n be described u n d e r tw o h e a d in g ^ T h o ra c ic W all (b) T he T h o ra c ic C a vitv The Thoracic Wall The wall o f the th o ra c ic c avity is c o m posed o f the th o rac ic vertebral colum n, th e ste rn u m , th e ribs, a n d th e in tervening m asculature. T hese p a rts a re in tu rn largely covered by th e m ascu latu re o f the vertebral c o lu m n a n d th a t o f th e u p p e r lim bs respectively. The framework o f the Thorax In le t o f the Thorax I T he su p e rio r th o ra c ic a p e rtu re o r th o ra c ic inlet is form ed by the bod y o f the first th o ra c ic v e rte b ra, th e first rib s and costal cartilages a n d th e e xtrem ely th ic k u p p e r p a r t o f the m an u b riu m sterni. The a p e rtu re is o p e n b ecause the stru c tu re s e n te rin g or leaving th e th o ra x th ro u g h th e inlet a re su rro u n d e d by loose connective tissue, re su ltin g in p o te n tia l spaces th ro u g h w hich cervical infections o r tu m o rs m ay descend in to th e m ed i­ astinum . O u tlet o f the Thorax In c o n tra st to th e inlet th e o u tle t o f the th o ra x is c o m ­ pletely closed by th e d iap h ra g m , w hich closely invests th o se structures passing betw een th e th o ra x a nd a b d o m e n . I t might, how ever, be p o in te d o u t h e re th a t in con se q u en c e o f the c u rv a tu re o f th e d ia p h ra g m the low er ribs actu ally afford m uch p ro te c tio n to th e u p p e r a b d o m in a l o rg a n s, and are also th ere fo re fu n c tio n ally a p a r t o f th e a b d o m in a l wall. R ib s a n d C ostal A rticulations T he first seven ribs are a tta c h e d to th e ste rn u m th ey are know n as tru e o r v e rte b ro -ste m a l ribs. T h e re m a in in g five pairs a re classified as false ribs. T h e cartila g es o f th e 8th, 9th a nd 10th ribs a rtic u la te w ith th e cartila g es o f th e ribs im m ediately a bove them a nd so fo rm a su b g ro u p o f ve rte b ro - ch ro n d ra l ribs. T h e last tw o p a irs end a m o n g the muscles o f the a b d o m in a l wall a n d th ey fo rm a su b g ro u p o f floating or vertebral ribs. T he a rticu la tio n s w ith th e bo d ies a n d transverse processes o f the ve rte b rae b e lo n g to th e synovial v a rie ty o f jo in ts. T he m obility p ro v id ed by th is a rra n g e m e n t is dim inished by the a tta c h m e n t o f th e u p p e r ten rib s to th e ste rn u m o r to each o ther. Slight m o v em e n t is p ro v id ed fo r by th e elasticity o f the costal cartilages. The S tern u m T he ste rn u m c onsist o f m a n u b riu m , b o d y a n d xiphoid process. T he very th ic k co n ca v e u p p e r b o rd e r is called the su p ra sternal n o tc h , it fo rm s a n im p o rta n t la n d m a rk . T he low er b o rd e r o f th e m a n u b riu m a rtic u la te s a t a n a ngle w ith the body—called th e ste rn al angle. T h e ste rn o -m a n u b ria l jo in t so form ed play s a n im p o rta n t p a r t in th e m echanism o f re sp iratio n , b ecause it allow s th e b o d y o f th e ste rn u m to move forw ard. Below th e b o d y lies th e x ip h o id pro cess w hich extends dow nw ards for a v a ria b le distan c e in to th e post-w all o f the sheath o f th e rectu s a b d o m in is. T h e tip o f th e xiphoid process is never selected as a la n d m a rk b ecause it is v a ria b le in length. The In terco sta l Spaces . T h e in tercostal m uscles o c c u p y th e spaces betw een the s. the e x ternal inte rco stal ru n s d o w n w ard a n d fo rw a rdr. ' - u u v i w a i a i i u n s u u w u w a i u a i i u l u i w a i u hr*1 ° ne r to n c x t> *n th e sam e d ire c tio n as the ex te rn al ooiique o f the a b d o m e n . T h e e x te rn al in te rco stal m uscle fails to re ac h th e ste rn u m a n te rio rly , being replaced here by a m em b ra n e th ro u g h w hich the in te rn al in te rc o sta l m a y be seen. Sim ilarly, the in te rn a l inte rco stal m uscle w hich ru n s u p w a rd a nd fo rw a rd fro m o n e rib to th e next, reaches p o ste rio rly o nly a b o u t to the angles o f th e ribs, behind w hich it is re p la ce d by a p o s te rio r in te rco stal m e m b ran e . T h e in te rn a l in te rc o sta l m uscle is divided by th e inte rco stal nerves a n d vessels in to tw o p a rts a n inner a n d o u te r p a rt. T h e in n erm o st p a rt is som etim es called th e in n e rm o st intercostal. The N erve a nd B lood S u pply o f the Thoracic W all T h e u p p e r nine p o ste rio r in te rco stal a rte rie s fro m the su p re m e inte rco stal a n d th o ra c ic a o r ta end by a n a s to m o sin g w ith th e a n te rio r in te rc o sta l b ra n ch e s fro m th e in te rn al m a m m a ry a n d the m u sc u lo -p h re n ic . W hile th e low er tw o a n d the su b c ostal a rte ry , c o n tin u e in to th e m u sc u la tu re o f the a b d o m in a l wall. T h e a n te rio r in te rc o sta l veins e nd in th e m u sc u lo p hrenic a nd the venae c o m ita n te s o f th e in te rn al m a m m a ry a rte ry . T he p o ste rio r in te rco stal veins differ in th eir a rra n g e m e n t on the tw o sides o f th e b ody, a n d a re d ra in e d by th e A zygos and H eniazygos system s. The D iaphragm Is th e d o m e sh a p e d m u sc u lo -a p o n e u ro tic p a rtitio n betw een the th o ra x and a b d o m e n . I t has a ro u n d e d c u p o la o n e ach side below th e lu n g s; a n d a depressed m ed ia n p o rtio n o n w hich th e h e a rt lies. T h e m edian p o r tio n rises to th e level o f th e x ip h istern al jo in t, w hich c o rre sp o n d s to the b o d y o f th e n in th th o ra c ic v e rte b ra. T h e rig h t c u p o la rises to th e 5th rib below th e rig h t n ip p le a n d th e le ft c u p o la rises to th e 5 th in te r­ space 1" below th e nipple. S tructure a nd A tta c h m en t T h e m u sc u la r fibres a re a rra n g e d p e rip h e ra lly a b o u t a c en tral ten d o n . T h ey a rise fro m th e p o ste rio r surface o f the x ip hoid process fro m th e in n er surfaces o f th e cartilag es a nd th e a d ja ce n t b o n y p a rts o f th e low er six rib s, fro m the u p p e r lu m b a r v e rte b ra e by m eans o f th e c ru ra o f th e d ia ­ p h ra g m a n d th e m ed ia n , late ra l a n d m edial a rc u a te ligam ents. B etw een th e ste rn al a n d c ostal o rigin o f the d iap h ra g m lies a sm all gap, o c cu p ied , b y c o nnective tissue a n d tra n s ­ m ittin g th e su p e rio r epig a stric vessels. T h e p o te n tia l g ap is k n o w n as th e ste rn o c o stal triangle. A sim ilar gap is som etim es fo u n d betw een th e lu m b a r orig in a n d th e last rib w hich is called th e v e rte b ro -co sta l triangle. T hese g aps a re im p o rta n t because th e y m a y result in to h ernias (Fig. 1). - S t e r n a l o r i g i n -------S t e r n o - c o s t a l t r i a n g l e ' - - C o s t a l o r i g i n " - C e n t r a l te n d o n • w i t h I . V . C . ~ ; a p e r t u r e O e s o p h a g e a l a p e r t u r e V e r t e b r o - c o s t a l t r i a n g l e A o r t i c a p e r t u r e l i g . 1 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 3. ) Page 4 P H Y S I O T H E R A P Y December, 1960 A pertures In a d d itio n to sm all a p e rtu re s fo r the tran sm issio n o f the sp la n ch n ic nerves a n d p a rts o f th e azygos system o f veins, th e d ia p h ra g m p re sen ts th ree larg e r a p e rtu re s. T h e a o rtic h ia tu s lies a t a b o u t th e level o f th e tw elfth th o rac ic v e rte b ra betw een the tw o c r u ra o f the d ia p h ra g m . T h e a o r ta , th o ra c ic d u c t a n d o fte n c o n trib u tio n s to the azygos a n d hem i-azygos veins p ass th ro u g h th e a o rtic h iatus. T h e o e so p h a g ea l h ia tu s lies in the m u sc u la r p a r t o f th e d ia p h ra g m o p p o site the 10th th o rac ic v e rte b ra. T h e m u s­ c u la r fibres a p p e a r to a c t as a sp h in c te r w hich p re v en ts re g u rg ita tio n o f th e sto m ac h c o n te n ts w h e n th e d ia p h ra g m c o n tra c ts. In a d d itio n to the o e so p h a g u s th is h ia tu s tra n s ­ m its th e v a g u s n e rv e a n d the oe so p h a g ea l b lo o d vessels co n n ec tin g the vessels o f th e sto m a c h w ith th o se o f th e th o ra x . T h e fo ra m e n fo r the in ferio r vena c av a is situ ate d o p p o site th e 8th th o ra c ic v e rte b ra , slightly to the rig h t in th e c en tral te n d o n . I t e n su res th a t th e in ferio r vena c av a is stre tc h ed w hen th e d ia p h ra g m c o n tra c ts — fa cilitatin g the flow o f v e n o u s b lo o d in to th e th o ra x w ith in sp ira tio n . Innervation a n d B lo o d S upply T h e m o to r nerve su p p ly is e n tirely th ro u g h the p h re n ic n erve w hich also supplies m o st o f th e d ia p h ra g m w ith sensory fibres. T h e m arg in s o f th e d ia p h ra g m a re su p p lied w ith sensory fibres th ro u g h th e low er 5 th o r 6 th in te rco stal nerves. T h e b lo o d su p p ly is fro m several so u rc es: T h e largest vessels a re the in ferio r p h re n ic a rte rie s w hich arise fro m th e first p a r t o f the a b d o m in a l a o rta , th e su p e rio r ph re n ic , the p e ric ard ia co p h re n ic , tw igs fro m the low er in te rco stal vessels a n d th e m u sc u lo p h re n ic ru n n in g late ra lly a lo n g the a tta c h m e n t o f th e d ia p h ra g m to th e cartila g es o f the false ribs. T h e in ferio r p h re n ic veins a re th e c h ie f d ra in a g e o f the d iap h ra g m . Function T h e a c tio n o f th e d ia p h ra g m is resp o n sib le fo r th e g reatest p a r t o f th e m ov em e n t o f the lu n g s in re sp ira tio n . The Thoracic Cavity D e e p to th e ribs a n d th e in te rco stal m uscles th e e ndo- th o ra c ic fascia fo rm s a r a th e r ind istin c t layer w hich essentially serves o nly to u n ite the p le u ra to th e th o rac ic wall. O ver th e apices o f th e lungs, w here th ey p ro tru d e in to th e n eck th ro u g h th e th o ra c ic a p e rtu re the fascia is thickened a nd k n o w n as the s u p ra p leural m e m b ra n e o r Sibsons fascia. T h e th o ra c ic c avity is divided in to rig h t a n d left p le u ra l cavities se p a ra te d com pletely by a m id d le p a rtitio n the m ed ia stin u m . T h e p leu ra l cavities a re lined w ith p le u ra w hich is s u b ­ divided in to th ree p a r ts ; p a rie ta l, visceral a n d c o nnecting. {Fig. 2. 3.) T h e P a r i e t a l P l e u r a : T h e p a rie ta l p le u ra lines the in n e r su rfa c e o f th e w alls o f th e p leu ra l cavities. I t is s u b ­ divided a c c o rd in g to the a re a it c overs: (a) C o sta l p leu ra , (b) M e d ia s tin a l p le u ra , (c) D ia p h ra g m a tic p le u ra , (d) C erv ical p leu ra . T h e V isceral p le u ra o r th e p u lm o n a ry p le u ra invests th e lungs. T h e c o n n e c tin g p le u ra covers th e r o o t o f th e lu n g a n d its low er p o rtio n s fo rm s th e p u lm o n a ry ligam ent. P l e u r a l R e c e s s e s : T h e p a rie ta l p le u ra is in c o n ta c t w ith the visceral p le u ra o ver th e su rfa ce o f the lung, b u t a n te rio rly it e x te n d s betw een th e c hest wall a n d the p e ri­ c ard ial sac it a lso e x te n d s fa rth e r inferiorly, betw een th e th o ra c ic wall a n d th e highly curved late ra l a n d p o ste rio r p a rts o f th e d iap h ra g m . T h ese p o te n tia l sp aces n o t occupied by lung c o n s titu te th e so-called p le u ra l recesses a n d a re n a m e d acc o rd in g ly the c o sto m e d iastin al a n d co sto d ia ­ p h ra g m a tic recesses. (Fig. 2 an d 3.) C e r v i c a l p l e u r a ' C o s t a l p le u r a - C o s t o - d i a p h r ^ r e c e s s ---- S u p r a - p l e u r a l m embrane ■f-----*■— v v -------M e d i a s t i n a l p l e u r a 1 C o n n e c tin g p l e u r a 2 V i s c e r a l p l e u r a ----- D ia p h r a g m a tic p l e u r a y ig .2 M ediastinum T h e p leu ra l sacs w ith th eir c o n ta in ed lungs o c cu p y a large p o rtio n o f th e th o ra c ic cavity. T h e rig h t a n d left p le u ra l cavities a re se p a ra ted fro m e ach o th e r by a m iddle p a rtitio n w hich is called the m ed iastin u m . Sub-divisions o f the M e d iastinum T h e m ed ia stin a l se p tu m is m a d e u p o f a larg e n u m b e r o f stru c tu re s em b e d d ed in c o nnective tissue. I t e x tends fro m th e ste rn u m to th e v e rte b ral c o lu m n b eh in d a n d fro m the inlet o f the th o ra x to th e d ia p h ra g m below . T h e p rin cip al stru c tu re s in th e m ed ia stin u m a re th e h e a rt in th e p e ric a rd iu m , th e a o r ta a n d o th e r g re a t vessels, the o e so p h a g u s a n d tra c h e a , several im p o rta n t nerves, rem ain s o f th e th y m u s gland a n d n u m e ro u s ly m p h glands. T h e m e d ia stin u m is divided in to f o u r p a rts . T h e su p e rio r m ed ia stin u m is th e p a r t a b o v e a n im a g in a ry p la n e th a t passes fro m th e low er b o rd e r o f the m a n u b riu m sterni to the low er surface o f th e bod y o f th e fo u rth th o ra c ic v e rte b ra. T h e p a r t b elow th a t p la n e is sub-divided in to th e m iddle m ed ia stin u m occu p ied by th e p e ric a rd iu m a n d its c o n te n ts. , T h e p h re n ic n erve passes o ver th e sides o f it. * T h e a n te rio r m ed ia stin u m lies in f ro n t o f the p e ric ard iu m a n d th e p o ste rio r m ed ia stin u m lies b eh in d th e p e ric ard iu m . T h e m ed ia stin u m as a w hole c o n ta in s all the im p o rta n t stru c tu re s o f th e th o ra x w ith th e ex ce p tio n o f th e lungs them selves. (Fig. 4, 5 a n d 6.) S u b d i v i s i o n s o f t h e m e d i a s t i n u m . R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 3. ) December, 1960 P H Y S I O T H E R A P Y Arch of aorta-^-") P h r e n i c n e r v e y p e r i c a r d i u m - ^ O e s o p h a g u s a n d t r a c h e a ----- V agus ------- P u lm o n a r y r o o t ^ — —Di a p h r a g m F i g . 5 i Structures seen through the left mediastinum. The Trachea a n d Lungs T he trac h ea begins in the n eck a t the low er end o f the larynx. It en ters the th o ra x o p p o site th e u p p e r b o rd e r o f the m a n u b riu m sterni a n d te rm in a te s a t the low er b o rd e r o f the m a n u b riu m o p p o site the 4 th th o rac ic v e rte b ra by dividing in to a rig h t a n d left b ro n c h u s. Its th o rac ic p a rt therefore lies in th e su p e rio r m ed ia stin u m . T he trachea, b e ing an e lastic stru c tu re , elo n g ates d u rin g inspiration a n d its b ifu rc a tio n m ay th u s descend to the level o f the bod y o f the fifth o r even th e sixth th o rac ic vertebra. Bronchi E ach b ro n c h u s passes d o w n w ard s a n d sid ew ard s to the hilum o f the c o rre sp o n d in g lu n g a nd thence d o w n w ard s in the substance o f the lung to w a rd s its base. T h e p rim a ry bronchi can th ere fo re be divided in to e x tra p u lm o n a ry a nd intra p u lm o n a ry p o rtio n s , k e p t p a te n t by rings— a n d plates o f cartilage, respectively. T he right b ro n c h u s is sh o rte r th an th e left b ro n c h u s, it is m ore vertical th an the left a n d is slightly w ider. It gives off one b ra n c h , w hich arises close to the h ilu m o f the lung a n d is called th e e p a rte ria l b ro n c h u s b ecau se it o rig in ­ ates im m ediately a b o v e the p o in t w here the right p u lm o n a ry artery crosses in fro n t o f the b ro n c h u s. The left b ro n c h u s gives off n o b ra n ch e s in the hilum . The Lungs T he lungs a re a p a ir o f c o m p a rativ ely light organs. T h e 6 *^e h ealthy lung su b sta n c e is re m a rk ab le . T he lungs, w hen h ealthy, lie free in the c avity o f the chest and a re atta ch e d o nly by th eir roots. Each lung p re sen ts fo r e x am in atio n a n apex, a base, a costal surface a n d a m edial su rfa ce se p a ra ted by a n te rio r, P °ste rio r a n d in ferio r b o rd e rs. J ™ a Pex rises in to the ro o t o f the n eck fo r a n inch a nd Th ? ° o v e the level o f the a n te rio r p a r t o f the first rib. . e _Pase ° f e ach lung has a sem i lu n a r o u tlin e a n d is Pled to the u p p e r surface o f the d iap h ra g m . Lo b es o f the Lungs T h e left lung is divided in to tw o lobes by a lo n g deep fissure w hich p e n e tra te s its su b sta n c e to w ith in a sh o rt distan c e o f the hilum . A n o b liq u e fissure a n d a h o riz o n ta l fissure divides the right lu n g in to th ree lobes. J u s t as the lobes c o n stitu te m a jo r segm ents o f th e lung w ith th eir ow n b ro n c h ia l, a rte ria l a n d v e n o u s supply, so do the b ro n c h i w ith in a lo b e b ra n c h a nd re b ra n c h to supply sm aller a nd sm aller segm ents o f lung tissue. I n p ractice o nly the m a jo r b ro n c h o p u lm o n a ry segm ents su p p lied by te rtia ry b ro n c h i a re n a m e d o r n u m b ere d . •(C ontinued fr o m p age 6) a tria l septal defects, a o rtic stenosis a n d re g u rg ita tio n , m itra l re g u rg ita tio n a n d o th e r com p lica te d co n g en ital h e art lesions. O w ing to the m ark e d d ra w b a c k o f h a v in g to w o rk on a n actively b e atin g b u t e m p ty heart, th e te c h n iq u e o f injecting a 2-J-% so lu tio n o f p o tassiu m c itra te in a rterialised b lood in to the asc en d in g a o r ta o f a pa tie n t o n th e h e art-lu n g m ac h in e w as in tro d u c e d by M elrose a b o u t five years ago, as this p ro c e d u re b rin g s a b o u t c ard iac sta n d still w hich m ark e d ly facilitate s th e p e rfo rm a n ce o f th e in tra -c a rd ia c o p e ra tio n . M o re recently it h a s been show n th a t be m erely c la m p in g o ff th e asc en d in g a o r ta a n d so de p riv in g th e h e art o f oxygen s p o n ta n e o u s c a rd ia c sta n d still will be p ro d u c e d w h ich will recover a g ain sp o n ta n e o u sly a fte r re m o v a l o f the clam p. W e shall n o w sh o w you a film, very kin d ly lent to us by W in th ro p P ro d u c ts, o f an o p e ra tio n pe rfo rm e d by D r. Je ro m e K a y in the U .S .A ., e m ploying the p rinciple described a b o v e o f a n oxic c a rd ia c a rre st w ith incision o f th e left ventricle to rem ove a tu m o u r fro m th e cavity o f this ventricle, exte n d in g in to b o th the left a triu m and a o r ta via th e m itral a n d a o rtic valves. I ♦ t ♦ I ♦ I♦ ( ♦ I♦ (♦ I♦ I ♦ I ♦ I ♦ I ♦ I ♦ I ♦ $ ♦ I ♦ I ♦ I♦ I ♦ I ♦ I ♦ I ♦ I♦ I BARF0 RD& JONES (SURGICAL SUPPLY CO.) Makers of: ARTIFICIAL LIMBS and ORTHOPAEDIC APPLIANCES SU R G IC A L INSTRUMENT REPAIRERS. P E R S O N A L A T T E N T IO N G IV E N T O ALL CASES. 1 5 8 P R E S I D E N T S T R E E T Corner N U G G ET STREET Phone 22-5 238 P.O. Box 5484. I♦ I♦ I♦ I♦ I♦ I♦ I♦ I♦ I♦ I♦ ♦ I♦ I♦ I♦ I♦ I♦ I♦ I♦ I♦ I♦ I♦ I♦ 0♦ e R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 3. )