642 



DISSECTION OF THE ORBIT. 



Lachrymal 

 nerve 



ends in 

 eyelid : 



offset joins 



superior 



maxillary. 



The lachrymal nerve (fig. 227, 3 ) after entering the orbit in : 

 separate canal of the dura mater, is directed forwards in the oute 

 part of the cavity, and beneath the lachrymal gland in the uppe 

 eyelid, where it pierces the palpebral fascia, and is distributed to tin 

 structures of the lid. 



The nerve furnishes branches to the lachrymal gland ; and iiea; 



FIG. 227. FIRST VIEW OF THE ORBIT (ILLUSTRATIONS OF DISSECTIONS). 

 Muscles : Nerves : 



A. Superior oblique. 1. Fourth. 



B. Levator palpebrse. 2. Frontal. 



3. Lachrymal. 



4. Supratrochlear. 



c. External rectus. 

 D. Superior rectus. 



F. Lachrymal gland. 



6. Offset of lachrymal to join 

 temporo-malar. 



Nasal, after 

 wards. 



Dissection. 



the gland it sends downwards one or two small filaments ( 6 ) to join 

 the temporo-malar branch of the superior maxillary nerve. 



The nasal nerve is not fully seen at this stage of the dissection, and 

 will be noticed later (p. 644). 



Dissection. Divide the frontal nerve about its middle, and throw 

 the ends forwards and backwards : by raising the posterior piece 

 of the nerve, the separate origin of the nasal branch from the 



