THE EYE. 207 



VESSELS AND NERVES OF THE EYE. 



What Nerves supply the Muscles of the Eye ? The 

 3d Cranial, or Motor Cculi, supplies the superior, inferior and internal recti, 



and the inferior oblique muscles. 



4th Cranial, or Trochlear supplies the superior oblique muscle. 

 6th Cranial, or Abducens, supplies the external rectns. 



Describe the Arteries of the Eye. The Eye is supplied by the Oph- 

 thalmic and Anterior Cerebral branches of the internal carotid artery, and 

 the Infra-orbital branch of the internal maxillary (from the external carotid). 

 The 



OPHTHALMIC, arises from the cavernous portion of the Internal Carotid, and 

 enters the optic foramen, giving off the following-named branches : 



Lachrymal, to the lachrymal gland, the upper eyelid, and the conjunctiva, 

 anastomosing with the palpebral arteries. 



Supra- orbital, supplies the superior rectus and levator palpebrse muscles, 

 the forehead and pericranial tissues. 



Anterior and Posterior Ethmoidal, to the dura mater, the nose, the ante- 

 rior ethmoidal cells, and the frontal sinus. 



Palpebral, superior and inferior, to the eyelids. 



Frontal, to the tissues of the forehead. 



Nasal, to the lachrymal sac, and the nose. 



Short Ciliary, 12 or 15, pierce the sclerotic at the lamina cribosa, supply- 

 ing the choroid and the ciliary processes. 



Long Ciliary, 2, pierce the sclerotic, and pass forwards between it and the 

 choroid, to supply the iris, forming two arterial circles thereon, the Cir- 

 culus Major Iridis at the ciliary border, and the Circulus Arteriosus Iridis 

 Minor near the pupillary margin. 



Anterior Ciliary, arise from the muscular branches, pierce the sclerotic, 

 and join the great arterial circle of the iris. 



Arteria Centralis Retina, pierces the optic nerve obliquely, and is dis- 

 tributed to the retina. 



Muscular Branches, 2, superior and inferior, supply the muscles of the 



eyeball. 



ANTERIOR CEREBRAL, branch of the Internal Carotid, sends nutrient capil- 

 laries to the optic nerve. 



INFRA-ORBITAL, branch of the Internal Maxillary artery, sends branches to the 

 inferior rectus and inferior oblique muscles, and to the lachrymal gland. 



Name the Principal Lymph-spaces of the Eyeball. The 



Canal of Schlemm, around the circumference of the iris. 

 Peri- choroidal Space, between the choroid and the sclerotic. 



