M. STERN0-3IAST0IDEUS. 221 



margin of the vertebral border, opposite the triangular space at the 

 vertebral end of the nieso^cai3nla ; (C) the next 2-2.3 cm. is at- 

 tached by a thin tendon, 2-3 mm. long, upon the ectal margin of the 

 vertebral border from opposite the middle of the space just men- 

 tioned, and thus slightly overlaj^piug part B, to within 8-10 mm. of 

 the gleno-vertebral angle of the scapula ; (D) the caudal o-Q mm. 

 is sej^arated from the rest by an interv^al 1-5 mm. wide, and is in- 

 serted by tlesliy or very short tendinous fibers upon the ectal aspect 

 of the gleno-vertebral angle in apposition witli the origin of the 

 teres. The scapular end of the muscle may be separated more or 

 less readily into four divisions corresponding with the parts of the 

 insertion just described, and the caudal division is sometimes quite 

 distinct, mth a decided extension toward the teres. 



M. STERNO-MASTOIDEUS. 



Remark. — This is strictly a muscle of tlie neck, but is here described on account of its 

 close relations with the muscles of the shoulder and with blood-vessels. 



§ 633. Synonymy. — The sternal part of the human sterno-deido-mastoid, G., A, 357; 

 Q., A, 1, 293 ; sterno-mast»idien, S.-D., A, II, 248 ; sterno-maxillaire, Ch., A, 210 ; sterno- 

 maxillaris, Ch. (Fl.), A, 198; sterno-wastoid, Miv., B, 134. 



Fibres. — Lateral aspect of cephalic half (66) ; lateral aspect (67) ; united sternal por- 

 tions (73) ; sternal portion (73). 



§ 623. General Description. — Tseniate, along the ventro-cephalic 

 border of the clam-trajyezius. from the prcBsternum to the mastoid 

 process of the temporal bone and the ventral part of the crista 

 lambdoidalis. 



Posture. — Latericumbent ; a block transversely under the neck ; 

 the head hanging. 



Exposure. — Connect the angle of the mouth with the occipito- 

 presternal line (§ 610) by an incision corresponding with the direction 

 of the margin of the upper lip. Note that the skin of the cheek, 

 especially in old males, is very thick. Dissect up both edges of the 

 skin for about 1 cm. 



The zygoma. (Fig. 30, oQ, 67) may be felt as a firm bony arch 

 between the M. temporalis (Fig. 67) dorsad, and the M. masseter 

 ventrad. 



Just caudad of the zygoma may be felt the cartilaginous meatus 

 auditor ius (Fig. 67, Mt. au. ex.\ partly embraced by the small, 

 pale and rather loose-textured ^^r/ro^/V? gland (Fig. 87, 107), Divide 

 the meatus close to the head, and reflect the flap, together with the 



