.^ 

 lacrymal. 



RAM. AD N. ZY&OMAT. 



127 



Carotts int. 



.GAN&L. GA55ERI 



K N. TRI&EMIN. 



N. RECURRENS 

 ARNOLD! 



471. The First Division (Ramus ophthalmicusj of the 

 Trigeminal Nerve. 



The I. ophthalmic branch, the smallest of the three divisions of the 

 fifth nerve, is a sensory nerve ; it passes forwards and upwards along the outer 

 wall of the cavei'nous sinus, communicates with the sympathetic nerve and Nervus 

 trochlearis, and gives off a recurrent filament, Ramus recurrens Arnoldi, to the 

 dura mater. Before its entrance into the spheiioidal fissure (Fissura orli- 

 talis superior) it is divided into three branches ; these are : 



a) The lachrymal, N. lacrymalis, which runs along the upper border 

 of the external rectus muscle, gives off a twig to the orbital nerve and passes 

 to the lachrymal gland, conjunctiva and skin at the outer canthus of the eye. 



b) The frontal, N. frontalis, situated below the roof of the orbit, divides 

 into : the s u p r a t r o c h 1 e a r branch, which, running above the M. oUiquus 

 superior, leaves the orbit above the Troclilea to be distributed to the skin of the 

 upper eyelid and the forehead; the supraorbital branch, which, usually 

 divided into two twigs, passes through the supraorbital notch to the forehead, being 

 distributed to the skin of the fore and upper parts of the scalp. 



c) The nasal or na so- ciliary, N. naso-ciliaris, lies at first on the 

 outer side of the optic nerve, passes through the origin of the external rectus 

 muscle with the abducens nerve, forms the long root of the ciliary gang- 

 lion, Radix longd s. sensitiva Ganglii ciliaris (see Fig. 469), reaches the inner 

 side of the optic nerve, giving off 1 2 ciliary nerves, and is finally divided 

 into the ethmoidal nerve, which at first passes through the anterior ethmoidal 

 foramen into the cranial cavity and then through the cribriform plate into the 

 nasal cavity, supplying the Septum narium, external wall of nasal cavity, and 

 finally the integument of the nose; and the inf ratrochlear nerve, passing 

 below the Trochlea to the structures at the inner angle of the eye. 



