BRANCHES OF THE EXTERNAL CAROTID. 



497 



reaches the groove, or canal, in the anterior inferior angle of the parietal bone : 

 it then divides into branches which spread out between the dura mater and internal 

 surface of the cranium, some passing upward over the parietal bone as far as the 

 vertex, and others backward to the occipital bone. The posterior branch crosses 

 the squamous portion of the temporal, and on the inner surface of the parietal 



Incisor. 



FIG. 287. The internal maxillary artery and its branches. 



Pterygo-palatilie 



ffmdll Mti 

 Middle Meniugtal 

 Tympan 



Inferior Jfcni 



FIG. 288. Plan of the branches. 



bone divides into branches which supply the posterior part of the dura mater and 

 cranium. The branches of this vessel are distributed partly to the dura mater, 

 but chiefly to the bones ; they anastomose with the arteries of the opposite side, 

 and with the anterior and posterior meningeal. 



The middle meningeal on entering the cranium gives oft the following collat- 

 eral branches : 1. Numerous small vessels to the Gasserian ganglion, and to the 

 dura mater in this situation. 2. A branch (petrosal branclt], which enters the 

 hiatus Fallopii, supplies the facial nerve, and anastomoses with the stylo-mastoid 

 branch of the posterior auricular artery. 3. A minute tympanic branch, which 

 runs in the canal for t.he Tensor tympani muscle, and supplies this muscle and the 

 lining membrane of the canal. 4. Orbital branches, which pass through the 

 sphenoidal fissure, or through separate canals in the great wing of the sphenoid to 

 anastomose with the lachrymal or other branches of the ophthalmic artery. 5. 

 Temporal or anastomotic branches, which pass through foramina in the great wing 

 of the sphenoid, and anastomose in the temporal fossa with the deep temporal 

 arteries. 



32 



