314 



THE MUSCLES AND FASCIAE. 



The muscles contained in each of these 

 1. Superficial Region. 



Platysma myoides. 

 Sterno-cleido-mastoid. 



Infra-hyoid Region. 



2. Depressors of the Os hyoides and 

 Larynx. 



Sterno-hyoid. 

 Sterno-thyroid. 

 Thyro-hyoid. 

 Omo-hyoid. 



Supra-hyoid Region. 



3. Elevators of the Os hyoides and 



Larynx. 



Digastric. 

 Stylo-hyoid. 

 Mylo-hyoid. 

 Genio-hyoid. 



Lingual Region. 



4. Muscles of the Tongue. 



Genio-hyo-glossus. 



Hyo-glossus. 



Chondro-glossus. 



Stylo-glossus. 



Palato-glossus. 



groups are the following: 



5. Muscles of the Pharynx. 

 Inferior constrictor. 

 Middle constrictor. 

 Superior constrictor. 

 Stylo-pharyngeus. 

 Palato-pharyngeus. 



6. Muscles of the Soft Palate. 

 Levator palati. 



Tensor palati. 

 Azygos uvulae. 

 Palato-glossus. 

 Palato-pharyngeus. 

 Salpingo-pharyngeus. 



7. Muscles of the Anterior Vertebral 



Region. 



Rectus capitis anticus major. 

 Rectus capitis anticus minor. 

 Rectus capitis lateralis. 

 Longus colli. 



8. Muscles of the Lateral Vertebral 



Region. 



Scalenus anticus. 

 Scalenus medius. 

 Scalenus posticus. 



9. Muscles of the Larynx. 

 Included in the description of 



the Larynx. 



1. Superficial Cervical Region. 



Platysma myoides. Sterno-cleido-mastoid. . 



Dissection. A block having been placed at the back of the neck, and the face turned to 

 the side opposite that to be dissected, so as to place the parts upon the stretch, make two trans- 

 verse incisions : one from the chin, along the margin of the lower jaw, to the mastoid process, 

 and the other along the upper border of the clavicle. Connect these by an oblique incision 

 made in the course of the Sterno-mastoid muscle, from the mastoid process to the sternum ; the 

 two flaps of integument having been removed in the direction shown in Fig. 194, the superficial 

 fascia will be exposed. 



The Superficial Cervical Fascia is a thin, aponeurotic lamina which is hardly 

 demonstrable as a separate membrane. Beneath it is found the Platysma myoides 

 muscle. 



The Platysma myoides (Fig. 195) is a broad, thin plane of muscular fibres 

 placed immediately beneath the superficial fascia on each side of the neck. It 

 arises by thin, fibrous bands from the fascia covering the upper part of the Pectoral 

 and Deltoid muscles ; its fibres pass over the clavicle and proceed obliquely 

 upward and inward along the side of the neck. The anterior fibres interlace, 

 below and behind the symphysis menti, with the fibres of the muscle of the 

 opposite side ; the posterior fibres pass over the lower jaw, some of them being 

 attached to the bone beloAV the external oblique line, others passing on to be 

 inserted into the skin and subcutaneous tissue of the lower part of the face, 

 many of these fibres blending with the muscles about the angle and lower part 

 of the mouth. Sometimes fibres can be traced to the Zygomatic muscles or to 

 the margin of the Orbicularis oris. Beneath the Platysma the external jugular 

 vein may be seen descending from the angle of the jaw to the clavicle. 



