THE SALIVARY GLANDS 1225 



The tongue, being very vascular, is often the seat of nevoid growths, and these have a tendency 

 to grow rapidly. 



The tongue is frequently the seat of ulceration, which may arise from many causes, as from 

 the irritation of jagged teeth, dyspepsia, tuberculosis, syphilis, and cancer. Of these, the cancerous 

 ulcer is the most important, and probably also the most common. The variety is the squamous 

 ipithelioma, which soon develops into an ulcer with an indurated base. It produces great pain 

 which speedily extends to all parts supplied with sensation by the trigeminal nerve, especially to 

 the region of the ear. The pain in these cases is conducted to the ear and temporal region by 

 the lingual nerve, and from this nerve pain radiates to the other branches of the inferior maxil- 

 lary nerve, especially the auriculotemporal. Possibly pain in the ear itself may be due to impli- 

 cation of the fibres of the glossopharyngeal nerve, which by its tympanic branch reaches the 

 tympanic plexus. Cancer of the tongue spreads through the organ very rapidly because of the 

 almost constant muscular movements. 



Cancer of the tongue may necessitate removal of a part or the whole of the organ, and many 

 different methods have been adopted for its excision. The better method is by the scissors, 

 usually known as Whitehead's method. The mouth is widely opened with a gag, the tongue is 

 transfixed with a stout silk ligature, by which to hold and make traction on it and the reflection 

 of mucous membrane from the tongue to the jaw, and the insertion of the Geniohyoglossi first 

 divided with a pair of curved blunt scissors. The Palatoglossi are also divided. The tongue 

 can now be pulled well out of the mouth. The base of the tongue is cut through by a series of 

 short snips, each bleeding vessel being dealt with as soon as divided, until the situation of the 

 ranine artery is reached. The remaining undivided portion of tissue is to be seized with a pair of 

 Wells' forceps, the tongue removed, and the vessel secured. In the event of the ranine artery 

 being accidentally injured early in the operation, hemorrhage can be at once controlled by 

 passing two fingers over the dorsum of the tongue as far as the epiglottis and dragging the root of 

 the tongue forcibly forward. 



In cases where the disease is confined to one side of the anterior portion of the tongue this 

 operation may be modified by splitting the tongue down the centre and removing only the affected 

 half. If the posterior portion of the tongue is attacked by cancer the entire tongue must be 

 removed, even if but one side of the organ is apparently involved. The exchange of lymph 

 between the halves of the posterior portion of the tongue makes it certain that the opposite half 

 becomes involved soon after the origin of the disease. Whatever operation is performed for 

 cancer of the tongue, the lymph nodes must be removed from both sides of the neck. This is to 

 be done, even if but one side of the tongue is removed. 



Finally, where both sides of the floor of the mouth are involved in the disease, or where very 

 free access is required on account of the extension backward of the disease to the pillars of the 

 fauces and the tonsil, or where the mandible is involved, the operation recommended by Syme 

 must be performed. This is done by an incision through the central line of the lip, across the 

 chin, and down as far as the hyoid bone. The mandible is sawed through at the symphysis, and 

 the two halves of the bone forcibly separated from each other. The mucous membrane is sepa- 

 rated from the bone, the Geniohyoglossi detached from the bone, and the Hyoglossi divided. 

 The tongue is then drawn forward and removed close to its attachment to the hyoid bone. Ad- 

 jacent lymph nodes can be removed, and if the bone is implicated in the disease, it can also be 

 removed by freeing it from the soft parts externally and internally, and making a second section 

 with the saw beyond the diseased part. . 



THE SALIVARY GLANDS (Fig. 946). 



The principal salivary glands communicating with the mouth, and pouring 

 their secretion into its cavity, are the parotid, sub maxillary, and sublingual. 



The Parotid Gland (ylandulae parotis) is the largest of the three salivary glands, 

 varying in weight from half an ounce to an ounce. It lies upon the side of the face, 

 immediately below and in front of the external ear. The main portion of the gland 

 is superficial, somewhat flat and quadrilateral in form, and is placed between 

 the ramus of the mandible in front and the mastoid process and Sternomastoid 

 muscle behind, overlapping, however, both boundaries. Above, it is limited by 

 the zygoma; below, it extends to about the level of a line joining the tip of the mas- 

 toid process to the angle of the mandible. The remainder of the gland is wedge- 

 shaped, and extends deeply inward toward the pharyngeal wall. 



The gland is enclosed within a capsule continuous with the deep cervical fascia; 

 the layer covering the outer surface is dense and closely adherent to the gland; 



