Muscles of tbe Neck. 



253 



Porus 

 acusticus 

 externus 



Processus 

 mastoideus 



Pi-ocessu& _ 

 styloideus 

 M. masseter 



M. digastricus 

 (venter posterior) 



M. splenius capitis 

 M. styloliyoideus 



M. sternocleidoniastoideus 



M. levator scapulae 



M. scalenus posterior 



M. scalenus 

 medlus 



il. scalenus 

 anterior 



M. digastricus 

 Corpus (venter 

 ossis anterior) 

 livoidei 



M. thyreohyoideus 



M. omohyoideus 

 (venter superior! 



M. sternohyoideus 



Acromion 



M. omohyoideus (venter inferior) 



Clavicuhi 



299. Muscles of the neck {2^'^ layer), viewed from the right side. 



(The platysma has been removed.) 



M. digastricus (see also Tigs. 298 and 301). Form: two rounded bellies, venter pos- 

 terior and venter anterior, with a long intermediate tendon. Position: below, behind and 

 medianward from the mandibula. The venter posterior arises in the ineisura mastoidea oss. 

 teraporaUs and goes over in front and below into an intermediate tendon, which is fastened 

 by a loop -like strip of the fascia colli to the coi-pus oss. hyoidei; the venter anterior arises 

 from this intermediate tendon and usually also from the corpus oss. hyoidei and goes to the 

 fossa digastrica mandibulae. Action: when the hyoid bone is fixed, it depresses the lower 

 jaw; when the lower jaw is fixed, it draws the hyoid bone upward. Innervation: venter, 

 2>osterit)r : r. digastricus n. facialis; venter anterior: n. mylohyoideus (V. 3). 



M. styloliyoideus (see also Figs. 298, 300 and 301). F o r m : flat, oblong, thm. Position: 

 behind and below the mandibula, just in front of and above the posterior belly of the m. tUgastricus. 

 Origin: processus stjdoideus. Insertion: forward, downward and medianward to the corpus 

 oss. hyoidei ; in the neighborhood of its insertion it surrounds the m. digastricus by two limbs. 

 Action: it draws the hyoid bone backward and upward. Innervation: r. stylohyoideus n. facialis. 



Spalteholz, Atlas. 17 



