PLATE XLV. 



SECOND VIEW OF THE PTERYGOID REGION, TEMPORAL 

 MUSCLE, AND PART OF RAMUS OF JAW REMOVED. 



This plate shows a deeper dissection of the same subject as the previous drawing. 

 The coronoid process has been cut through at its base and turned upwards with the 

 temporal muscle, and the ramus of the jaw sawn through just below the pterygoid fossa 

 and above the inferior dental foramen and removed, exposing the first and second portions 

 of the internal maxillary artery. 



The first portion of the artery passes between the ramus of the jaw and the so-called 

 long internal lateral ligament ; it is generally described as giving off four branches, but 

 it is much more usual to find only two, viz., the inferior dental and middle meningeal, 

 the latter giving the tympanic and small middle meningeal. All these four arteries pass 

 through bony foramina. 



The second portion of the artery varies in its course, being sometimes superficial and 

 sometimes deep to the external pterygoid muscle, the proportion given on the conjoint 

 investigation of the Anatomical Committee being 54 per cent, above, and 44 per cent, 

 below ; this portion of the artery gives off four sets of muscular branches buccal, 

 pterygoids, temporal, and masseteric, and one arterial comes to the lingual nerve. 



The third portion of the artery lies in the spheno-maxillary fossa, and gives six 

 branches which all pass through bony foramina alveolar, infra-orbital, posterior 

 pharyngeal, Vidian, posterior palatine, naso-palatine. 



The long internal lateral or spheno-mandibular ligament is a thin loose band of 

 fibrous tissue which stretches across from the spinous process of the sphenoid to the 

 inner edge of the inferior dental foramen. It is too lax to be of much use as a ligament, 

 and is really the fibrous remains of a part of the Meckelian bar of cartilage. 



