1096 



SURGICAL ASD TOPOGRAPHICAL AXATOMY 



drawn from the last molar tooth to the angle of the jaw, by entering a knife nearly 

 three-quarters of an inch behind and below the tooth, and cutting towards it on the 

 l)one (Moore). Another and far simpler and surer method is to draw the tongue 

 out of the mouth and expose the nerve where it lies superficially under the mucous 

 membrane thus made ]jrominent between the side of the tongue and gums, the 

 centre of the incision being opposite to the last molar tooth (Roser, Letievant). 



Behind the last molar tooth can be felt the coronoid process, and higher up, 

 just behind and inside the tooth, the hamular process of the sphenoid. This 

 process is a landmark to the site of the posterior palatine canal, which lies just in 

 front of it, and which transmits the posterior and descending palatine branch of 

 the internal maxillary, together with the anterior or great palatine nerve. The 

 vessel and nerve run forwards in grooves towards the anterior palatine canal, and 

 their position must be remembered in raising the flaps during the operation for 



Fig. 671.— Sectiox of the Skull and Bratx ix the Median Plane. (Braiine.) 



PITUITARY BODY 

 OCCIPITAL BONE 



EUSTACHIAN TUBE 



Genio-hyo-glos8us 



Mylo-hyoid 



Arytenoideus muscle 



RIMA GLOTTIDIS 



THYROID BODY 

 Sterno-thyroid muscle 



Falx cerebri 



Superior longitudinal 



L^ Inferior longitudinal 

 \ 1 t sinus 



'" — Corpus eallosum 



Optic chiasma 

 Corpus mammiUai'e 



Posterior lobe of 



cerebrum 

 Pons Varolii 

 Cerebellum 

 Torcular Herophili 



^lil*^ ^^vi-'// ' Medulla 

 — '• '•^ ' ■ ' — — oblongata 



POSTERIOR RING OF ATLAS 

 DY OF AXIS 



BODY OF SECOND THORACIC VERTEBRA 



closure of a cleft in the hard palate. To ensure the vitality of the flaps the 

 incisions must be made close to and parallel with the ui)per alveolus. 



On the inner side of the coronoid, between it and the tuberosity of the upjier 

 jaw, is a recess where a temporal abscess will point, having travelled down under 

 the fascia and zygoma. When a patient breathes deeply through the mouth, and 

 the head is thrown l)ack, the soft palate is raised, the pillars are separated, and the 

 uvula and fauces, with the anterior and posterior pillars, the tonsils, and the back 

 of the pharynx are exposed. This portion of the pharyngeal mucous membrane 

 would lie over the lower ]iart of the second and the upper ]iart of the third cervical 

 vertebrae, the anterior arch of the atlas corresponding to the level of the ]-)ostcrior 

 nares, and the body of the axis to the level of the soft palate (fig. 671). If a 

 finger be introduced past the soft palate to this part of the spine and turned 

 upwards and downwards, it is possible to examine the upper four or five and, in 

 children, six vertebrae, as far as the anterior surfaces of their liodies. ' The part of 

 the column which is accessible to a straight instrument introduced through the 



