MUSCLES OF THE NECK. 



157 



The retrahens aurem (posterior auris,) arises by three or four 

 muscular slips from the mastoid process. They are inserted into 

 the posterior surface of the concha. 



It is in relation by its external surface with the integument, and 

 by its internal surface with the mastoid portion of the temporal bone. 



Actions. The muscles of the auricular region possess but little 

 action in man ; they are the analogues of important muscles in 

 brutes. Their use is sufficiently explained by their names. 



Muscles of the Neck. The muscles of the neck may be arranged 

 into eight groups corresponding with the natural divisions of the 

 region; they are the 



1. Superficial group. 



2. Depressors of the os hyoides and larynx. 



3. Elevators of the os hyoides and larynx. 



4. Lmgual group. 



5. Pharyngeal group. 



6. Soft palate group. 



7. Prsevertebral group. 



8. Proper muscles of the larynx. 



And each of these groups consists of the following muscles : viz. 

 1. Superficial Group. 



Platysma myoides, 

 Sterno-cleido-mastoideus. 



2. Depressors of the os 

 hyoides and larynx. 



Sterno-hyoideus, 

 Sterno-thyroideus, 

 Thyro-hyoideus, 

 Omo-hyoideus. 



3. Elevators of the os 

 hyoides and larynx. 



Digastricus, 



Stylo-hyoideus, 



Mylo-hyoideus, 



Genio-hyoideus, 



Genio-hyo-glossus. 



4. Muscles of the tongue. 



Genio-hyo-glossus, 



Hyo-glossus, 



Lingualis, 



Stylo-glossus, 



Palato-glossus.* 



5. Muscles of the Pharynx. 

 Constrictor inferior, 

 Constrictor medius, 

 Constrictor superior, 

 Stylo-pharyngeus, 

 Palato-pharyngeus. 



6. Muscles of the soft Palate. 

 Levator palati, 



Tensor palati, 

 Azygos uvulae, 

 Palato-glossus,* 

 Palato-pharyngeus, 



7. PrcBvertelral Group. 

 Rectus anticus major, 

 Rectus anticus minor, 

 Scalenus anticus, 

 Scalenus posticus, 

 Longus colli. 



8. Muscles of the Larynx. 

 Crico-thyroideus, 

 Crico-arytsenoideus, posticus, 

 Crico-aryta3noideus, lateralis, 

 Thyro-arytsenoideus, 

 Arytaenoideus. 



* Described by Homer as the Constrictor isthmii faucium. G. 



