MUSCLES OF ANTERIOR NECK. 



483 



FIG. 147. 



head forward. If the sternal portion act alone it will turn 

 the face to the opposite side ; if the clavicular act by itself 

 it will bend the 

 head to the same 

 side. If the mus- 

 cles of the back 

 be in strong ac- 

 tion, this muscle 

 can assist in still 

 further throwing 

 the head back- 

 ward, as seen in 

 that variety of 

 tetanus called 

 opisthotonos. It 

 is concerned in 

 the production of 

 wry neck. It has 

 in front or cover- 

 ing it, the skin, 

 platysma, superficial fascia, external jugular vein, portion 

 of the parotid gland, branches of the portio-dura, and cervi- 

 cal plexus of nerves, and at its upper part it is perforated 

 by the spinal accessory nerve, which, however, sometimes 

 passes behind it. 



The sterno-liyoideus is a long, narrow, flat muscle, sit- 

 uated on either side of the median line of the neck, and 

 exposed by removing the deep cervical fascia. It arises 

 from the first bone of the sternum on its posterior surface, 

 and the sternal end of the clavicle, ascends and is inserted 

 into the inferior margin of the body of the os-hyoides. 



FIG. 147 represents the principal muscles of the neck, after turning aside 

 the platysma myoides. a Mastoid process. 6 Hyoid bone, c Sterno hyoideus 

 muscle, d Sterno thyroideus. t Omo hyoideus. / Origin of omo-hyoidens. 

 g Thyroid gland, h Anterior belly of digastricus. i Posterior belly of the 

 same, j Where the digastric tendon passes through the stylo-hyoideus. k 

 Mylo-hyoideus. I Genio-hyoideus. m Hyo-glossus. n Thyro-hyoideus. 

 9 Thyroid cartilage, p Scalenus anticus. q Rectus capitis-anticus major, 

 r Levator anguli scapula?, s Splenius. 



