214 ANATOMICAL TECHNOLOGY. 



about 45 degrees with the mesoscapula. On the ectal surface of the 

 spino-irapeziiis^ aloug the line of union of the muscular and ten- 

 dinous parts, is received the insertion of the acromio-trapezius 



(Fig. Ql). 



M. ACROMIO-TRAPEZIUS. 



§ 613. Synonymy. — The intermediate part of the human trapezius, G.,'i"Z; Q., I, 

 187; acromiO'CucuUaire, S.-D., A, II, 333 ; portion cervicale du trapeze, Ch., A, 216, and 

 Fig. 90; cervical trapezius, Ch. (FL), A, 303; anterior part of the trapezius, Miv., 

 B, 137. 



Figures. — Ectal aspect (66) ; eutal aspect and insertion (67) ; insertion area (44). 



General Description. — Thin ; sub-trapezoidal ; from the dor si- 

 meson, in the caudal part of the cervical region and sometimes also 

 the cephalic part of the thoracic^ to the metacromion, and the adja- 

 cent surface of the M. spino-trapezius. 



Dissection. — The caudal border has been indicated in describing 

 the spino-trapezius, which is often slightly overlapped by it. It 

 nearly coincides with a line drawn between the vertebral ends of the 

 two mesoscapulse. Lift it at the vertebral border of the scapula, 

 and note that, 8-10 mm. from the mescm, it becomes a thin tendon 

 which may be traced across the meson to its platetrope without 

 severing any definite attachments to the subjacent parts. Ventrad 

 it may be traced to a point about 1 cm. caudad of the mesoscapula, 

 and 1.5 to 2 cm. from the nearest part of the vertebral border of the 

 scapula where it terminates upon the ectal surface of the spino- 

 trapezius. 



The cephalic border of the muscle may be recognized as forming 

 the caudal margin of a narrow intemiuscuJar interval, the hiatus 

 trapezii, at the side of the neck, about midway between the convex- 

 ity of the shoulder and the meson. This interval is filled with con- 

 nective tissue and fat, in which are imbedded a lymphatic gland 

 and an artery. 



Follow this border to the meson, noting that, for about 1 cm. 

 therefrom, it is either continuous with the caudal border of the next 

 muscle {clavo-trapezius) or slightly overlapped by it. They may 

 be separated, however, without cutting fibers. Ventrad of the hia- 

 tus this border is usually overlapped for 3-5 mm. by the levator 

 clamculcB, the border of which must be lifted with care. Transect 

 the acromio-trapezius at the vertebral border of the scapula. 



§ 614. Origin. — In two or three parts : In the caudal five eighths 

 the thin tendon is continuous across the meson with its platetrope. 



