252 



Muscles of the Neck. 



Processus 

 niastoideu 



Corpus ossis hyoidci 



M. tligaslricus 

 venter anterior) 



M. mylohyoideus 



Carlilago thyreoidea, 

 Glandula thvreoidea 



M. digastricus 

 (venter posterior) 



M. stylohyoideus 



Loop for tlie 

 111. digastricus 

 ]M. thyreohyoideus 



M. omoliyoideus 

 (venter superior) 

 M. cricothyreoideus 



M. sternohyoideus 



M. sternocloido- 

 mastoideus 



M. trapezius 



C'lavicula 



M. ouioliyoideus 

 (venter inferior) 



M. sternothyreoideus 



298. Muscles of the neck, (2"i layer), viewed from in front. 



(The head has hecn bent backward; the phitysma has been removed.) 



M. steriiocleidom.astoi(leus (see also Figs. 296 and 299). Form: long, flat-cylindrical, 

 strong. Position: on the lateral and anterior surfixce of the neck, covered in its lower half by 

 the platysnia. Origin: by two heads: medial head: by a long tendon from the airtau^r surface 

 of the maniilitiuiLUsterni, partly covering the articulatio sternoclavicularis ; lateral head: by a 

 short tendon Irom the upper surface of the sternal extriMiiity of the clavicle. Between the two 

 heads there is usually a triangular space, which is broader below, and which corresponds to 

 the fossa supraclavicularis minor (see P'ig. 2S1). Insertion: the lateral head passes under the 

 medial; the two unite at about the middle of the neck and go obliquely upward, backward 

 and lateralward to become attached by a short tendon to the lateral surface of the processus 

 mastoideus and to tlio linea nuchae sui)renia. Action: the muscle of one side acting alone 

 turns the head to the opposite side ami the face at the same time upward : the muscles of 

 the two sides acting together draw the head obliquely forward and downward, or, if the head 

 be fixed, they elevate the clavicle and sternum (and with them also the thorax). Innervation: 

 n. accessorius. 



