HEAD AND ANTERIOR CERVICAL STRUCTURES. 59 



neck, trace the superficial cervical artery, expose the origin of the omo-hyoid 476 and follow the 

 supra-scapular artery 546 (536) and nerve 834 (815) to the point where they enter the supra- 

 spinous fossa. 



Superficial cervical artery, 548 (538) 



Levator anguli scapulae, 305 ; Figs. 263 and 266. (307-8-9) 



Origin. Insertion. Structure. Nerve-supply. Action. Relations. Variations. 

 The rhomboidei, 305-6-7 ; Fig. 263. (309-10) 

 Rhomboideus minor: 



Origin. Insertion. Structure. Nerve-supply. 

 Rhomboideus major: 



Origin. Insertion. Structure. Nerve-supply. Variations. 

 Action. Relations of the two rhomboidei. 



Divide the rhomboids at their origin and turn outward to the insertion. Note the nerve to the rhom- 

 boids and follow the posterior scapular artery along the border of the scapula. 



Nerve to the rhomboids, 834. (815) 

 Posterior scapular artery, 547. (538) 



Expose the outer surface of the serratus magnus, then draw the scapula forward and outward and ex- 

 pose the inner surface. Demonstrate the origin and the insertion. 



Serratus magnus, 313-14-15, Fig. 267. (31617) 

 Origin ; First part, Second part, Third part. 

 Insertion ; First part, Second part, Third part. 

 Structure. Xerve-supply. Action. Relations. Variations. 



Divide the trunks of the brachial plexus and tie them to a small splinter to preserve their relative posi- 

 tion. Cut the axillary artery at its commencement. Divide the muscles connecting the extremity with 

 the trunk and remove it. The remaining structures of the back will now be exposed. 



Serratus posticus superior, 436-7-8 ; Fig. 305. (432) 



Origin. Insertion. Structure. Nerve-supply. Action. Relations. Variations. 

 Serratus posticus inferior, 438; Fig. 305. (434) 



Origin. Insertion. Structure. Nerve-supply. Action. Relations. 



Divide the serratus posticus superior at its origin, and turn it outward to the insertion. 



Splenius: splenius capitis, splenius colli, 439-40; 305. (435) 

 Splenius Capitis : 



Origin. Insertion. Structure. Nerve-supply. Action. 

 Splenius Colli : 



Origin. Insertion. Structure. Nerve-supply. Action. 



Relations of the splenius. Variations. 



Divide the splenius at its origin and throw it upward to the insertion. 



The vertebral aponeurosis, 438 ; Fig. 305. (434) 

 Posterior aponeurosis or lumbar fascia, 434. (430) 



Divide the vertebral aponeurosis and lumbar fascia by an incision about an inch from, and parallel 

 with, the spinous processes ; reflect outward and expose the erector spinre and its divisions. 



Erector spinae, 440-1 ; Fig. 306. (436) 



Origin. Insertion. Structure. Nerve-supply. Action. Relations. 

 Outer Division, 441-2-3. (436-7-8) 

 Ilio-costalis, or sacro-lumbalis : 



Origin. Insertion. 

 Accessorius ad ilio-costalis or ad sacro-lumbalis. 



Origin. Insertion. 

 Cervicalis ascendens : 



Origin. Insertion. Structure. Nerve-supply. Action. Relations. 

 Middle Division ; 443-4-5. (438-9-40) 

 Longissimus dorsi : 



Origin. Insertion ; externally, internally. 

 Transversalis colli : 



Origin. Insertion. 



