12 THE SURGICAL ANATOMY OF THE HORSE 



division of the internal maxillary artery which we are now considering 

 takes its course through the palatine canal, which it leaves at the inferior 

 palatine foramen. It then courses along the palatine groove, and at the 

 level of the corner incisor tooth it curves inwards towards the median 

 line, and meets and inosculates with the corresponding vessel of the 

 opposite side. The vessel which results from this inosculation passes 

 forwards through the incisor foramen to supply the upper lip. 



It is important to note the position of these vessels, since the palatine 

 artery is not infrequently injured. Such injury might be due to accident 

 whilst performing the operation of scarification in the treatment of 

 lampas, or to the presence of sharp foreign bodies, such as bits of glass 

 in the food, etc. But whatever the cause, haemorrhage is more easily 

 arrested if the artery is completely cut through, since the longitudinal 

 fibres in the arterial wall withdraw the severed end of the vessel into the 

 surrounding tissues, and the latter being here quite tense they exert 

 considerable pressure on the wall of the vessel, with the result that the 

 lumen of the latter is thus closed. If the artery is only partially severed 

 it is therefore best to complete the section. If the hemorrhage should 

 not be effectively arrested by this method, more pressure should be 

 placed upon the vessel by plugging the mouth and bandaging round 

 the upper and lower jaws to keep the mouth closed. 



The chamber of the mouth when closed is almost wholly taken up 

 in accommodating the tongue. The superior surface of this organ is 

 quite free, and so is the inferior surface for from four to five inches 

 from the tip, when the mucous membrane of the inferior aspect of 

 the tongue passes on to the floor of the mouth, forming the fold called 

 the frcenum lingua;. On either side of the frsnum is seen the papilla, 

 which is called the barb. 



The tongue itself gradually increases in thickness from its tip 

 backwards for about three-quarters of its length, and then during its 

 posterior fourth its thickness decreases. 



Hanging behind the backwardly descending portion of the tongue 



