INTERNAL CAROTID ARTERY. 259 



16. The Great or Middle Artery oi the Dura Mater; a branch of the 

 internal maxillary.* 



17. The Artery of the Upper Jaw. 



18. The Infra Orbital Artery ; it is seen to pass out upon the face. 



Fig. 2, is a Plan of the Internal Maxillary Artery. 



1. The Meningeal Artery, or great middle artery of the dura mater. f 



2. The Inferior Maxillary Artery. % 



3. Irregular Arteries : the Pterygoid Arteries. 



5. The Deep Internal Temporal Artery. 



6. The Artery of the Cheek. 



7. The Artery of the Upper Jaw. 



8. The hifra Orbital Artery. 



9. The Superior Palatine Artery. 



10. The Origin of the Superior or Upper Pharyngeal Artery. 



The Internal Carotid Artery 



Is sometimes called the Artery of the Brain, as it is almost 

 entirely appropriated to that viscus. 



From its origin to the commencement of its ramifications, the 

 course of this blood-vessel is peculiarly tortuous. In conse- 

 quence of which, the force of the blood in it is greatly dimin- 

 ished before it arrives at the brain. 



An instance of this curvature occurs immediately after 

 its separation from the external carotid, when it protrudes out- 

 wards so much as to be exterior to that vessel ; after this it 

 ascends to the carotid canal, and in its course is in contact, or 

 very near the par vagum and sympathetic nerves. 



* It is this artery which rises through the spinous hole in the sphenoid bone, 

 and then runs on the lower angle or spinous process of the parietal bone : here 

 it generally lies in a deep channel, and gives occasion to a kind of rule in sur- 

 gery, to avoid applying the trephine at this part. 



f This artery enters the skull by the foramen spinale of the sphenoid bone, 

 and is the same that makes the deep furrow in the inside of the parietal bone. 

 Mr. Walker, of Edinburgh, communicated a case where an arrow shot into the 

 skull wounded this artery. 



I Lower Maxillary. This artery enters at the posterior foramen of the lower 

 jaw-bone, and courses within the bone, and appears on the chin, coming out 

 through the mental foramen. In pulling the last molaris of the lower jaw, if 

 the inner plate of the bone be broken off, and this artery torn up among the 

 cells of the bone, the patient may die of bleeding. 



