RELATIONS OF LUNGS TO CHEST-WALLS 



nil 



internal manimary, which run outwards, two small lirancht-s to each space, per- 

 foratini^ branches from the same vessel, one or two given off opi)osite to each space, 

 the loni,' tlioracic and external mammary (when present) from the axillary. 



The lymphatics may be divided "into two sets— (A) The majority which 

 go along the chief v(>ssels to the glands in the axilla, where the following groujjs 

 are to be found: (1) Axillary; (2) subscapular; (3) pectoral, along the long tho- 

 racic; (4) subclavian, or infra-, and supraclavicular. All these anastomose with 

 each other, and also with (B) a much smaller set of lymphatics, which pass from 

 the inner part of the breast, through the anterior ends of the intercostal space, to 

 the internal mannnary or anterior intercostal lymphatic glands. Thus they reach 

 the mediastinal and deeper Ivniphalics. 



Parts behind manubrium. — There is little or no lung behind the first bone of 

 the sternum, the s])ace being occui)ie(l by the trachea and large vessels, as f(jllows: 

 — The left innominate vein crosses behind the sternum just below its upper border. 

 Next come the great })rimary branches of the aortic arcli. Deeper still is the tra- 



FiG. 683.— Outline ok the Heakt, its Valves, and the Llngs (shaded). (Holdeii.) 



chea, dividing into its two bronchi o])])Osite to the junction of the first and second 

 bones of the sternum. Deepest of all is the O'sophagus. Al^out one inch from the 

 upper liorder of the sternum is the highest ])art of the aortic arch, lying on the 

 bifurcation of tlu^ trachea (Ilolden). 



Outline of the lungs. Their relation to the chest-wall. — The a]>ex of the 

 lung rises about an inch and a half (from half an inch to an inch and three-cjuar- 

 ters) above the first rib into the base of the posterior triangle lying behind the inner 

 end of the clavicle, the sterno-mastoid, and the anterior scalene, covered l)y the 

 pleura and deep cervical fascia, and having the subclavian artery arching over it. 

 From the apices the thin anterior borders converge inwards behind the sterno- 

 clavicular joints, and the first piece of the sternum to the junction of this with the 

 second, almost meeting at this point. Thence the two borders tlescend parallel and 

 close to each other (the right sometimes )>assing just beyond the middle line), and 

 thus covering over the heart and larg(> vessels, to a jtoint midway between the fourth 

 pair of costal cartilages, where they diverge, l>ut not to an eijual degree. The right 



