442 TOPOGRAPHICAL ANATOMY. 



a. Below (the m. omohyoideus) : 1. Loose fibro-cellular tissue, 

 wherein is a branch of ven. jugul. extern, (anter.) 2. The deep 

 layer offasc. cervical, and m. omohyoideus. 3. The external bor- 

 der of m. sterno-hyoid., and -thyreoideus. 4. The junction of w. 

 jugular, intern, and extern, behind articul. sterno-cleidoidea (in the 



angle the duct, thoracicus opens). 5. N. phrenicus outside (close 

 to scalenus antic. m.), 1" distant from n. vagus (close to carotis 

 commun.); between the two, n. sympathicus. 6. Right, the supe- 

 rior extremity of truncus anonymus (carotis and art. subclav. 

 dextra) ; left, carotis comm., art. subclav. sinistra. 7. Right, w. 

 recurrens ; left, ductus thorac., the superior extremity of the 

 pleura. 8. M. longus colli and vertebral column. The carotis 

 lies 1" removed from the anterior border of m. sterno-cleido-mast. ; 

 the right rather nearer. 



b. Above (between omohyoid. and splenius}: 1. Plex. cervical. 

 2. Art. cervical, ascend., m. red. antic, cap. magn., scaleni, levat. 

 scapul.^ splenius colli. 3. Proc. transversi and art. vertebralis. 

 Quite above, splenius capitis, &c. 



2. Trigonum cervicale inferius, supraclavicular fossa, a trian- 

 gle, the base of which is formed by the clavicular (the first rib), the 

 sides by the anterior border of rn. cucullaris and the posterior of 

 sterno-cleido-mast., and which is divided by the post, belly of m. 

 omohyoideus into an inferior smaller, and a superior larger triangle. 



Position of the parts: 1. Skin, m. platysmam. 2. Before, v. 

 jugular, extern.,- above, nn. subcutan. colli, accessor. Willisii. 3. 

 M. omohyoid. and the deep layer offasc. cervicalis. 4. Art. trans- 

 versa colli, supraclavicular., ven. subclavia (between the first rib 

 and clavicle). 5. In front, scalenus anticus (on the internal bor- 

 der of which n. phrenicus} ; behind, scalenus med. (and post.) ; be- 

 tween the two, above and outside the origin of plex. brachialis; 

 below and within, art. subclavia, upon the first rib, close to the 

 tubercle, separated by scalenus antic, from ven. subclavia. Ex- 

 ternal to the scaleni the artery lies close behind the vein, in the 

 direction of m. omohyoid. 6. The transverse processes of the 

 cervical vertebra, mm. intertransvers., art. profund. cervic. and 

 vertebralis. 



Posterior surface of the neck, nape, cervix. 



[Dissection. 1. An incision should be made in the middle line, through 

 the skin only, from the chin to the sternum. 2. From the mastoid process to 

 the acromion. 3. From the mastoid process to the centre of the upper border 

 of the sternum. 



Two triangular flaps of skin are thus formed, attached by their bases, the 

 one, above, to the horizontal ramus of the lower jaw ; the other, below, to the 



