398 



ANATOMY IN A NUTSHELL. 



3. The third set are (1) the posterior superior dental, usually two in 

 number. They pass downward and outward through the ptery go-maxillary 

 fissure into the zygomatic fossa where they give branches to the mucous mem- 

 brane of the gums and the posterior part of the mouth. They then enter the 

 posterior dental canals on the zygomatic surface of the superior maxillary bone 

 to communicate with the middle dental nerve and branches to the lining mem- 

 brane of the antrum of Highmore (superior maxillary sinus). It also gives off 

 three branches to the molar teeth which enter the foramina at the apices of the 

 fangs to supply the pulp. 



(b) The middle superior dental and the anterior superior dental are 

 given off in the infraorbital sulcus. The middle supplies the bicuspid teeth 

 and the mucous membrane of the antrum and the gums. After leaving the 

 infraorbital nerve it passes downward and forward in a canal in the superior 

 maxillary. These branches which supply the teeth anastomose with the anter- 

 ior superior and posterior superior dental branches. At the junction of the 

 middle and anterior is the ganglion of Bochdalek; at the junction of the middle 

 and posterior is the ganglion of Valentin. 



PLATE OCX III. 



RECURRENT TO SYMPATHETIC- 



The Trochlear or Fourth Cranial Nerve. 

 LESSON CXII. 



(c) The anterior superior branch is given off just before the infraorbital 

 nerve enters the infraorbital foramen. It descends to supply the incisor and 

 canine teeth. It gives branches to the gums and mucous membrane of the 

 antrum and the nasal branch which enters the nasal fossa through a small 

 foramen and supplies the mucous membrane of the forepart of the inferior 

 meatus and its floor. It communicates with the nasal branch from Meckel's 

 ganglion. 



The branches on the face are palpebral, labial, and nasal. 



The palpebral supplies the skin and mucous membrane of the lower eye- 

 lid. At the outer angle of the orbil it joins with the seventh and malar branch 

 of the orbital. 



