THE CILIARY BODY AND LENS 



819 



evidence in support of this reciprocal action has been furnished by- 

 Anderson. ^ ' 



In this connection, it should also be mentioned that the oculomotor 

 and short ciliary nerves innervate the ciliary muscle which is used in 

 accommodation. For this reason, the excitation of this nerve really 

 produces a double effect, i.e,, it constricts the pupil and also renders 

 the lens more convex. Concurrently, its division must be followed not 



Gasseriafi , 

 Gan^liotu. 



OjbhtAaL 



Zona ciltaru nerues. 

 ^-. I ^Dilator 



Ciliary (^ancUofu Art Ciliary Tierves 



Fig. 426. — Schema Showing the Path of the Preganglionic and Postganglionic 

 Fibers to the Ciliary Muscle and to the Sphincter and Dilator Muscles of the 

 Iris. {Modified from Schultz.) 



only by pupillar dilatation but also by a flattening of the lens, which 

 change renders it adapted for far vision. 



CHAPTER LXX 



THE CILIARY BODY AND LENS 



The Ciliary Body. — The space beween the ora serrata of the 

 retina and the base of the iris is occupied by the ciliary processes of 

 ;the choroid, its muscles, ligaments and glands. In this region, the 

 choroid is considerably thickened, measuring 6 to 7 mm. across. In 

 cross-section it displays a triangular outline, which is largely taken up 

 by strands of plain muscle tissue, forming the ciliary muscle. These 

 fibers are arranged in two ways, namely, longitudinally and transversely 

 to the long axis of the eyeball. The former arise from the fore-part 

 of the sclerotic coat close to the cornea, where they are attached to 

 the ligamentum pectinatum. They pursue a course almost directly 

 ^ Jour, of Physiology, xxx, 1903, 15. 



