DISSECTING MANUAL. 



the periosteum to the lachrymal gland, conjunctiva, and skin 

 at outer can thus; it communicates with the orbital (superior 

 maxillary) and temporal (facial). The frontal runs through 

 the sphenoidal fissure and then above the muscles, dividing 

 into the supra-orbital and supra-trochlear. The supra-orbital 

 runs through the supra-orbital groove to the skin of the fore- 

 head, eyelid, and scalp, communicating with the temporal 

 (facial) . The supra-trochlear runs over the Superior oblique 

 tendon and under the inner side of the supra-orbital arch to 

 the inner canthus and skin of the forehead and root of the nose, 

 communicating with the infra-trochlear (nasal). [679] 



The nasal runs through the sphenoidal fissure between the 

 heads of the External rectus and between the divisions of the 

 oculo-motor; then running inward above the optic nerve and 

 Internal rectus, below the Superior rectus and Superior 

 oblique, and through the anterior ethmoidal foramen, it crosses 

 the cribriform plate, descends through the nasal fissure to the 

 nose and divides into nasal branches. Branches : Long root of 

 ciliary ganglion, arising external to the optic nerve; Long 

 ciliary, two branches arising above the optic nerve and run- 

 ning beside it to the eyeball. Infra-trochlear, arising internal 

 to the optic nerve and running under the pulley of the Superior 

 oblique to the skin of the eyelids and root of the nose. Inter- 

 nal nasal, to the front of the septum. External nasal, supply- 

 ing the front of the outer nasal wall and then running between 

 the nasal bone and lateral cartilage to the skin on the lower 

 part of the nose. [680] 



Ciliary or Lenticular Ganglion. This is small and reddish 

 and lies between the optic nerve and External rectus, in front 

 of the ophthalmic artery. Roots : Short (motor) , derived from 

 the inferior division of the oculo-motor. Long (sensory) , derived 

 from the nasal branch of the ophthalmic. Sympathetic, de- 

 rived from the cavernous plexus and may fuse with the preced- 

 ing. Branches : Short ciliary, twelve to fifteen nerves which 

 run above and below the optic nerve to the eyeball. [680] 



[54] 



