INTERNAL MAXILLARY ARTERY. 93 



should be followed backwards with care behind the articulation, and the 

 dental and gustatory nerves beneath the muscle should be cleaned. The 

 small chorda tympani is then to be found joining the posterior part of the 

 gustatory nerve near the skull. 



The middle meningeal artery is to be sought beneath the external ptery- 

 goid. Sometimes the trunk of the internal maxillary artery lies beneath 

 that muscle, and in such case, it and its branches are to be traced out. 



The INTERNAL MAXILLARY ARTERY (fig. 17, A) is one of the terminal 

 branches of the external carotid, and takes a winding course beneath the 

 lower jaw and the temporal muscle to the spheno-maxillary fossa, where it 

 ends in branches for the face, the interior of the nose, and the palate and 

 pharynx. 



At first the artery is directed inwards beneath the jaw, between that 

 bone and the internal lateral ligament of the joint, and crosses the dental 

 nerve. Next, the vessel winds over the external pterygoid muscle, being 

 placed between it and the temporal muscle. And lastly, the artery enters 

 the spheno-maxillary fossa between the processes of origin of the external 

 pterygoid. The course of the artery is sometimes beneath, instead of over 

 the external pterygoid : in such a state the artery gains the spheno-maxil- 

 lary fossa by coming upwards through the origin of the muscle, as in the 

 woodcut. 



The branches of this artery are very numerous, and are classed into 

 three sets: thus one set arises beneath the jaw; another between the mus- 

 cles ; and another in the spheno-maxillary fossa. 



Two branches, viz., the inferior dental and middle meningeal, leave the 

 internal maxillary artery whilst it is in contact with the ramus of the jaw. 



The inferior dental branch descends between the internal lateral liga- 

 ment and the jaw, and enters the foramen on the inner surface of the ramus, 

 along with the dental nerve: it supplies the teeth, and ends in the lower 

 part of the face. 



As this artery is about to enter the foramen it furnishes a small twig, 

 mylo-hyoid branch, to the muscle of that name; this is conducted by a 

 groove on the inner surface of the bone, in company with a branch from 

 the dental nerve, to the superficial surface of the mylo-hyoid muscle, where 

 it anastomoses with the submental artery. 



The great meningeal artery is the largest branch, and arises opposite 

 the preceding. It ascends beneath the external pterygoid muscle, and 

 (oftentimes) between the roots of the auriculo-temporal nerve ; crossing 

 the internal lateral ligament, it enters the skull through the foramen spino- 

 sum of the sphenoid bone. When in the skull the artery ascends to the 

 vertex of the head, and supplies the bone and the dura mater (p. 29). 

 Before the meningeal artery enters the skull, it furnishes the following 

 small branches : 



a. The tympanic branch (inferior) passes into the tympanum through 

 the Glaserian fissure, and is distributed to the membrana tympani and that 

 cavity. 



b. A deep auricular branch arises with the former or separately enters 

 the meatus through the cartilage, or between this and the bone, and rami- 

 fies in the meatus and on the membrana tympani. 



c. The small meningeal branch begins near the skull, and courses through 

 the foramen ovale with the inferior maxillary nerve; it ramifies in the 

 dura mater in the middle fossa of the skull. 



Another small branch springs from the dental artery or the internal 



