1112 



SURGICAL AXD TOPOGRAPHICAL ANATOMY 



descends in an almost straight line as far as the sixth chondro-sternal joint. The 

 left is deeply notched (incisura cardiaca). The lower borders of the lung pass 

 downwards and outwards across the sides of the chest from the sixth chondro- 

 sternal joint to the tenth thoracic spine. In the nipi)le-line the lung reaches the 

 sixth ril), in the ])osterior fold of the axilla, the eighth, and opposite the angle of 

 thescajnda (the arms being close to the sides), the tenth rib. Thus, to map out the 

 lung, a line should l)e drawn from the apex, a point about an incli and a half above 

 the first rib, a little outside the sterno-mastoid muscle, obliquely inwards, behind 

 the sterno-clavicular joint, to near the centre of the junction of the first and second 

 bones of the sternum. Thence, on each side, a line should be draAvn slightly con- 

 vex as far as a similar point on the sternum lying opposite the articulation of the 

 fourth chondro-sternal joint. On the right side the line may be dropped as low as the 

 sixtli chondro-sternal joint; on the left (to show the incisura cardiaca) a line should 

 be drawn sloping outwards from the fourth chondro-sternal articulation along the 

 lower border of the fourth rib, across the fourth interspace, to a point about an 

 inch and a half lielow the left nipple (male) and an inch to its inner side. This 

 point, lying in the fifth space, marks the apex of the heart. The lower border of 

 the lung will be marked on the right side by a line drawn from the sixth chondro- 



FlG. 



684. — Diagram of the Relatioxs of the Thoracic Viscera to the 

 Walls of the Chest. (Bellamy.) 



Superior eul-de-sao of right lung — ___ 



RIGHT AURICLE 

 RIGHT AURICULAR APPENDAGE 

 Kight auriculo-ventrioular 

 orifice 



Limit of diaphragm in com- 

 plete respiration 



Limit of the anterior and in- 

 ferior border of right lung 

 in complete expiration 



Limit of right lung in 

 inspiration 

 Limit of diaphragm in com- 

 plete inspiration 



Limit of pleura 



^_, —Superior cul-de-sao of left lung 



-U- LEFT AURICLE 



X _' Pulmonary orifice 



Left auriculo-ventricular orifice 

 Orifice of aorta 



Limit of diaphragm in 

 complete expiration 



Limit of the anterior and infe- 

 rior border of left lung in 

 complete expiration 



Limit of left lung in 

 inspiration 



- Limit of pleura 



sternal articidation across the side of the chest down to the tenth thoracic si)ine. The 

 lower border of the left lung will follow a similar line, starting on a level with a simi- 

 lar joint (sixth chondro-sternal joint), but much farther out than on the right side, 

 i.e. in the lifth space, about three inches to the left of the middle line, or a point corre- 

 sponding to the heart's apex. This margin of the lung descends about an inch and a 

 half in deep inspiration, according to Godlee. The position of the great fissure in 

 each lung may be ascertained approximately by drawing a line from the second thora- 

 cic spine to the sixth rib in the nipple line; and the smaller fissure of the right lung 

 extends from the middle of the foregoing to the junction of the fourth costal car- 

 tilage with the sternum. It will be seen from the above tliat there is little lung 

 behind the manubrium. The connective tissue here between the lung margins 

 contains up to puberty the thymus, and, later, its remains. The pleura reaches 

 lower down than the lung. Thus its lower margin reaches along the seventh ril) 

 cartilage near the sternum; in the axillary line it has reached the lower margin of 

 the ninth rib; fartlier ])ack it reaches as low as the twelfth rib, or the eleventh tho- 

 racic spine. Thus it may be o])ened in operations in the loin, e.g. on the kidney, 

 or in removing the twelfth ril). Mr. Ilolden thus draws attention to this lower level 

 of the pleura: 'Since the j)l('ura lines the inside of the last rib, a musket-ball or 



