382 THE MUSCLES AND FASCIA 



6. Muscles of the Soft Palate. 8. Muscles of the Lateral Vertebral 



Ren ion. 

 Levator palati. 



Tensor palati. Scalenus anticus. 



Azygos uvulae. Scalenus medius. 



Palatoglossus. Scalenus posticus. 



Palatopharyngeus. 

 Salpingopharyngeus. 



7. Muscles of the Anterior Vertebral 9. Muscles of the Larynx (Intrinsic}. 



Included in the description of the 

 Rectus capitis anticus major. Larynx. 



Rectus capitis anticus minor. 

 Rectus capitis lateralis. 

 Longus colli. 



1. The Superficial Cervical Region. 

 Platysma. Sternomastoid. 



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 mandible, 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 Sternomastoid muscle, from the mastoid process to the sternum; the 

 two flaps of integument having been removed in the direction shown in Fig. 287, the superficial 

 fascia will be exposed. 



The superficial cervical fascia is a thin, aponeurotic lamina which is hardly 

 demonstrable as a separate membrane. It invests the Platysma. 



The Platysma (platysma) (Fig. 289) is a broad, thin plane of muscle fibres 

 situated on the 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 mandible, some of them are attached to the bone below the external oblique 

 line, others pass on to be inserted into the skin and subcutaneous tissue of the 

 lower part of the face, and many of these fibres blend with the muscles about the 

 angle and lower part of the mouth. Sometimes fibres can be traced to the Zygo- 

 matic muscles or to the margin of the Orbicularis oris. Beneath the Platysma 

 the external jugular vein may be seen descending hi a line from the angle of the 

 mandible to the middle of the clavicle. 



Relations. By its superficial surface, with the integument, to which it is united more closely 

 below than above; by its deep surface, with the Pectoralis major and Deltoid, and with the 

 clavicle. In the neck, with the external and anterior jugular veins, the deep cervical fascia, the 

 superficial branches of the cervical plexus, the Sternomastoid, Sternohyoid, Omohvoid, and 

 Digastric muscles. Behind the Sternomastoid muscle the Platysma covers in the posterior tri- 

 angle of the neck; on the/orr it is in relation with the parotid gland, the facial artery and vein, 

 and the Masseter and Buccinator muscles. 



Nerves. The lower division of tl e facial nerve supplies this muscle. 



Action. The Platysma produces \: slight wrinkling of the surface of the skin of the neck 

 in an oblique direction, when the entire muscle is brought into action. Its anterior portion, 

 the thickest part of the muscle, depresses the .namlible; it also serves to draw down the lower 

 lip and the angle of the mouth on each side, thus u.'ing one of the chief agents in the expression 



