HEAD AND ANTERIOR CERVICAL STRUCTURES. 19 



Remove the muscles of the nose and expose the nasal cartilages. 



The cartilages, 927-8 ; Figs. 512-13-14. (906-7) 



Superior lateral. Inferior lateral. Cartilage of the septum. 

 Also, the sesamoid and accessory quadrate. 

 Upper lateral cartilages. 

 I .ower lateral cartilages. 

 Inner plates. 

 Outer plates. 

 Sesamoid. 



Accessory quadrate. 

 Septal cartilage. 



Anterior border. 



A pad, which should he kept properly moistened with preservative fluid, should be placed over the 

 orbit and face, and retained in place by a bandage, until the part is wanted for further dissection. 



THE EAR, 907. (886) 



External Ear: Pinna and external auditory meatus. 

 Middle Ear, or tympanum, with the Eustachian tube. 

 Internal Ear, which includes the osseous labyrinth, within which is placed the 



membranous labyrinth. 



The External Ear, 907-8-9-10. (886-7-8-9) 

 Pinna, or auricle. 



Helix. Lobule. Concha. Scaphoid fossa. 



Antihelix. Antitragus. Triangular fossa. Tragus. Antitragus. 



The skin should be removed from the surface of the entire auricle, exposing the structures underneath. 



Cartilaginous framework. Lobule. Fissures of Santorini. 

 Ligaments : 



Anterior ligament. 

 Posterior. 



Muscles: Extrinsic muscles (attollens, attrahens, and retrahens aurem). 

 Intrinsic muscles : Helicis major. Helicis minor. 



Tragicus. Antitragicus. Transversus auris. 

 Obliquus auris. 

 Vessels : 



Arteries : Posterior auricular. Anterior auricular. 

 Veins. Also, Veins of the ear, 663. (650) 



Nerves : Great auricular. Posterior auricular of the facial. 

 Auricular branch of the pneumogastric. 

 Auriculo temporal. Small occipital. 

 (External Auditory Meatus.) 



The pinna should be left in place. The external auditory canal will be more fully considered at a later 

 period, in connection with the middle ear. 



THE NECK. 



Superficial Structures. 



landmarks in the middle line, 1124-5-6. (1101-2-3) 



Continue the median incision to the sternum and make a transverse incision along the anterior border 

 of the clavicle to the outer end. Turn the skin outward and backward from the median line, exposing 

 the superficial fascia. The platysma should then be exposed. 



Superficial fascia, 452. (447) 



Platysma myoides, 452-3-4. (447-8-9) 



(Origin.) Insertion. Structure. Nerve-supply. Action. Relations. Variations. 



Beginning at the mandible, carefully reflect the platysma downward to the clavicle and remove the 

 cervical portion, dividing it about half-an-inch above the clavicle. In reflecting the platysma great 

 care must be exercised not to remove or injure the nerves or veins immediately beneath it. 



External jugular vein, 654. (641) 



Chief variations of the external jugular vein. 



