DISSECTION OF THE HEAD AND NECK. 193 



5. The Posterior Dee}) Temporal Artery, given off from the upper side 

 of the parent trunk about half an inch before it enters the subsphen- 

 oidal canal. It enters the temporal muscle by passing in front of the 

 condyle of the temporal articular surface, and it communicates with the 

 masseteric division of the transverse facial artery by a slender branch 

 which passes through the corono-condyloid notch. 



The Internal Maxillary Vein passes between the two pterygoid 

 muscles; and, crossing below the articulation of the jaw, it joins the 

 superficial temporal vein to form the jugular. The junction takes place 

 in the substance of the parotid, a few lobules of the gland being inter- 

 posed between it and the termination of the external carotid artery. 



The Inferior Maxillary Division of the 5th Nerve (Plate 31). 

 This is a thick cord containing both sensory and motor filaments which 

 issues from the cranium by the forepart of the foramen lacerum basis 

 ■cranii. It passes obliquely downwards and backwards on the wall of the 

 guttural pouch, in front of the temporo-hyoideal articulation, and divides 

 about an inch below its point of exit into two branches of nearly equal 

 size — the inferior dental and lingual nerves. As it issues from the 

 foramen it gives off the following branches : — 



1. The Subzygomatic Nerve is detached from the superior aspect of 

 the trunk. It turns round behind the articulation of the jaw, and has 

 already been seen to join the 7th nerve, which it accompanies in its 

 distribution on the face. It sends a branch in company with the trans- 

 verse facial vessels. 



2. The Nerve to the Internal Pterygoid arises from the anteroinferior 

 aspect of the trunk. 



3. The Nerve to the Masseter and Temporal Muscles. This is given off 

 from the front of the trunk. It detaches branches to the temporal 

 muscle, and is then continued through the corono-condyloid notch to 

 end in the masseter. 



4. The Buccal Nerve is a larger branch than any of the foregoing. 

 It arises at the same point as the preceding nerve, and, passing through 

 the external pterygoid muscle, to which and the temporal muscle it 

 supplies branches, it is continued as a sensory nerve to the cheek. 



The Inferior Dental Nerve is the larger of the two branches into 

 which the trunk of the inferior maxillary nerve divides. Under cover 

 of the external pterygoid muscle, it crosses over the internal maxillary 

 artery, in company with the lingual nerve, which lies in front of it. 

 It then passes in between the two pterygoid muscles, where it places 

 itself in front of the inferior dental vessels. It has already been 

 seen issuing from between the muscles to gain the inferior dental 

 canal by passing between the inner muscle and the bone. 



The J/ylo-hyoid Nerve is detached from the posterior edge of the fore- 

 going nerve at its point of formation. It crosses the inferior dental 



o 



