THE BACK 



1407 



The axillary border of the scapula, covered by the latissimus dorsi and teres major, may 

 best be palpated with the arm hanging to the side. The vertebral border is brought into 

 prominence by placing the hand on the opposite shoulder. This border is held in apposition 

 with the thorax by the serratus anterior; consequently in parah'sis of that muscle, supplied bj' 

 the long thoracic nerve (5, 6, and 7 C), it becomes unduly prominent, giving rise to ''winged 

 scapula." Fig. 1126 shows the chief arteries around the scapula. The anastomoses on the 

 acromial process between the transverse scapular (supra-scapular) thoraco-acromial, and 

 circumflex humeral arteries are not shown. The numerous points of ossification, primary and 

 secondary, by which this bone is developed explain, in part, the frequency of cartilaginous and 

 other growths here. 



The anatomy of the loin behind, the ilio-costal region, is of prime importance, owing to the 

 numerous operations here. The lateral border of the sacro-spinalis and quadratus lumborum- 

 may be indicated on the surface thus. (Stiles.) That of the sacro-spinalLs by drawing a line 

 from a point on the iliac crest 8.2 cm. (3| in.) (four fingers'-breadth) from the middle line up- 

 ward and slightly laterally to the angles of the rib.s. That of the quadratus pa.ssing upward 

 and shghtly medially lies a little lateral to that of the sacro-spinalis (erector) at the crest, ' 



Fig. 1127. — Relations of the Abdominal Viscera to the Posterior Body Wall. 



Spleen 



and a httle medial to it at the twelfth rib. The ascending and descending colon he in the 

 shghtly depressed angle between the two muscles. The ilio-costal region varies greatlv in 

 space accordmg to the length of the lower ribs, shape of the chest, and development of the iliac 

 crest. Anmcision here— that for exploration of the kidney mav be taken as the tvpe— would be 

 an obhque one, about 10 cm. (4 in.) long, starting in the angle between the twelfth rib and the 

 sacro-spmahs muscle and passing forward and downward toward the anterior extremity of 

 the iliac crest In its upper part the incision should lie 1.2 cm. (§ in.) below the tweltfh rib. 

 1 he anterior fibres of the latissimus dorsi are divided behind, the posterior ones of the external 

 obhque in front. The yellowish-white lumbar fascia now comes into view, and is the first 

 important landmark. It and the fibres of the internal oblique and transversus which arise 

 from it are next carefully divided. The last thoracic nerve and lowest intercostal artery may 

 also require division. If the latter is cut close to the rib, the hsemorrhage is troublesome. The 

 transversalis fascia remains to be divided. To avoid the peritoneum, the deeper part of the 



