OF THE BACK. 



FIRST LAYER. 

 Trapezius. 

 Latissimus Dorsi. 



SECOND LAYER. 

 Levator Anguli Scapulas. 

 Bhomboideus Minor. 

 Rhomboideus Major 



THIRD LAYER. 

 Serratus Posticus Superior. 

 Serratus Posticus Inferior. 

 Splenius Capitis. 

 Splenius Colli. 



FOURTH LAYER. 

 /Sacral and Lumbar Regions. 

 Erector Spiiise. 



Dorsal Region. 

 Sacro-lumbalis. 



Musculus Accessorius ad Sacro-lum- 

 balem. 



Longissimus Dorsi. 

 Spinalis Dorsi. 



Cervical Region. 

 Cervicalis Ascendens. 

 Transversalis Colli. 

 Trachelo- mastoid. 

 Complexus. 

 Biventer Cervicis. 

 Spinalis Cervicis. 



FIFTH LAYBB. 

 Semispinalis Dorsi. 

 Semispinalis Colli. 

 Multifidus Spinas. 

 Rotatores Spinse. 

 Supraspinales. 

 Interspinales. 

 Extensor Coccygis. 

 Intertransversales. 

 Rectus Capitis Posticus Major. 

 Eectus Capitis Posticus Minor. 

 Obliquus Capitis Superior. 

 Obliquus Capitis Inferior. 



FIRST LAYER. 



Trapezius. 



Dissection (Fig. 226). Place the body in the prone 

 position, with the arms extended over the sides of the 

 table, and the chest and abdomen supported by several 

 blocks, so as to render the muscles tense. Then make 

 an incision along the middle line of the back, from the 

 occipital protuberance to the coccyx. Make a trans- 

 verse incision from the upper end of this to the mastoid 

 process ; and a third incision from its lower end, along 

 the crest of the ilium to about its middle. This large 

 intervening space should, for convenience of dissection, 

 be subdivided by a fourth incision, extending obliquely 

 from the spinous process of the last dorsal vertebra, 

 upwards and outwards, to the acromion process. This 

 incision corresponds with the lower border of the 

 Trapezius muscle. The flaps of integument are then 

 to be removed in the direction shown in the figure. 



The Trapezius is a broad, flat, triangular 

 muscle, placed immediately beneath the skin, 

 and covering the upper and back part of the 

 neck and shoulders. It arises from the inner 

 third of the superior curved line of the occi- 

 pital bone; from the ligamentum nuchae, the 

 spinous process of the seventh cervical, and 

 those of all the dorsal vertebra?; and from 

 the corresponding portion of the supraspinous 

 ligament. From this origin, the superior 

 fibres proceed downwards and outwards, the 

 inferior ones, upwards and outwards; and the 

 middle fibres, horizontally; and are inserted, 

 the superior ones, into the outer third of the 

 posterior border of the clavicle; tbr middle 



Latissimus Dorsi. 



Fig. 226. Dissection of the Muscles 

 of the Back. 



