MUSCLES OF THE RIGHT SUPERIOR LIMB 49 



2. Latissimus dorsi m.: Lumbodorsal fascia mainly; to 

 proximal end of humerus. Flexes brachium. The tendons of 

 the latissimus dorsi and those of the cutaneous maximus and 

 epitrochearis (a thin, superficial m. which inserts in the olecronal 

 process, Fig. 19) fuse and with the pectoralis minor form the 

 tendinous bicipital arch, through which the biceps muscle (20) 

 and principal vessels and nerves of the arm pass. Method: 

 Insert the grooved director dorsad under the belly of the latissi- 

 mus dorsi, in the triangle formed by the margins of this and 

 the pectoral muscles, and probe a considerable area of the 

 muscle free. Then push the grooved director dorsad through 

 the post axillary triangle between the posterior trapezius m. 

 (i^) and the latissimus dorsi. Transect near the vertebral end 

 of the scapula leaving the proximal portion fused with that of 

 the posterior trapezius {ih). 



3. Levator scapulae ventralis (Ls. major) m.: Basioccipital 

 bone, dorsad of basioclavicularis m. (4) ; to metacromial process. 

 Draws shoulder and brachium craniad. Transect. This is a 

 long slender muscle. It arises with the basioclavicularis m. 

 (4) and is fused with the anterior trapezius m. (la) the distal 

 third of its length. This (3) and the next muscle (4) arise under 

 and ventrad to the cleido- (6) and sternomastoid (7) mm. and 

 lie nearly parallel to each other. 



4. Basioclavicularis : Basiocciput, ventrad of levator scapu- 

 lae ventralis (3) ; to clavicle. Draws shoulder craniad or may 

 depress head or extend arm. Transect. This muscle continues 

 onto the arm as the clavodeltoid (12), and both muscles (4, 12) 

 form the basiohumeralis. 



5. Occipitoscapularis (levator scapulae minor, l.s. dorsalis, 

 rhomboideus capitis) m.: Supraoccipital region and mastoid 

 process to medial surface of inferior angle of scapula. Draws 

 vertebral border of scapula dorsocraniad. Transect. This is a 

 long ribbon-hke muscle lying immediately ventrad of the 

 anterior trapezius m. (la) from its origin to the cranial border 

 of the rhomboideus m. (9), where it passes over the levator 



