368 



ANATOMY IN A NUTSHELL. 



the chiasms will produce blindness in the inner half of each eye. A lesion of 

 the left optic nerve will produce blindness in the left eye and vice versa. A 

 lesion of the left optic tract will produce blindness in the left half of each eye 

 and vice versa. As this nerve pass< s from the brain it receives coverings from 

 the dura mater, arachnoid, and pia mater. It passes through the optic foramen 

 with the ophthalmic artery, being above and on the inner side of the artery. 

 The optic, motor oculi, trochlear, trifacial, and the abducent nerves 

 are all concerned with the eye -ball and its apparatus, thus making all the of 



PLATE CLXXXVIII. 



INTERNAL GCNICULATE BODY 

 4TH CRANIAL N 



SUPERIOR PEDUNCLE 



MEUDLLART VELUM 



great horizontal fissure. 

 Tim: Superior View of the Cerebellum. 



first six cranial nerves, excepting the first. The optic nerve is the nerve of sight. 

 The motor oculi, trochlear, and abducent are th< nerves to the mnscles of the 

 eyeball, and the fifth nerve supplies the ophthalmic, lenticular, or ciliary gang- 

 lion with one of iis roots, from which ganglion nerves pass to the iris. 



The eyeball is Located in the orbit which consists of seven bones, viz., (1) 

 frontal, (2) ethmoid, (3) sphenoid, (4) lachrymal, (5) superior maxillary, (6) 

 malar, and (7) palate. In the two orbits there arc but eleven bones, the frontal, 

 ethmoid and sphenoid being common to the two. The orbit is somewhat 

 pyramidal in shape with the base forward and apex backward. (Plate CCXXIX 

 The axial lines, if extended, would meei on the sella turcica of the sphenoid. 



