CAROTIDS, AND THEIR BRANCHES. 205 



ments of the middle of the side of the cranium, anastomosing 

 with the anterior branch, with its fellow of the other side, and 

 with the occipital artery. 



The Internal Maxillary Artery (flrteria Maxillaris Interna) 

 winds around the neck of the lower jaw, and, passing between 

 the pterygoid muscles, proceeds in a tortuous manner to the 

 deepest points of the zygomatic fossa. The first part of its 

 course is horizontally inwards; it then ascends in front of the 

 pterygoideus externus to the bottom of the temporal bone, or 

 the spinous process of the sphenoidal : it then passes forwards, 

 within the temporal muscle, to the upper part of the pterygo- 

 maxillary fossa. 



It sends off several branches, and commonly in the following 

 order: 



1. The Arteria Tympanica, to the tympanum, through the 

 glenoid fissure. 



2. The Arteria Meningea Parva, to the dura mater, throuh 

 the foramen ovale. It is most frequently a branch of the next. 



3. The Arteria Meningea Magna, or Media, to the dura ma- 

 ter, through the foramen spinale. This branch having entered 

 the cranium, is distributed upon the dura mater in the manner 

 marked off by the furrows upon the internal face of the tempo- 

 ral, the parietal, and the frontal bones. One of its branches en- 

 ters the aqueduct of Fallopius, through the Vidian Foramen, 

 and is distributed upon the internal parts of the organ of hear- 

 ing, anastomosing with the stylo-mastoid artery. 



4. The Arteria Maxillaris, or Dentalis Inferior, descends 

 along the internal face of the ramus-of the lower jaw, and 

 having sent off some ramifications of small size to the contigu- 

 ous muscles and the lining membrane of the mouth, it enters 

 the posterior mental foramen with the inferior dental nerve. 

 Going along the canal in the substance of the lower jaw, it de- 

 taches successively from its superior margin ramifications to 

 the teeth. At the anterior mental foramen a trunk is sent for- 

 ward as far as the symphysis, which supplies in its course the 



VOL. II. 19 



