VASCULAE TUNIC OE THE EYE. 



811 



layers, viz. : (a) the lamina suprachorioidea ; (&) the proper tissue of the chorioid ; 

 and (c) the lamina basalis (Eig. 681). 





Lamina basalis 



Lamina choriocapillaris 

 Intermediate stratum 



> Lamina vasculosa 



=; Lamina suprachorioidea 



Sclera 



FIG. 681. VERTICAL SECTION OF CHORIOID AND INNER PART OF SCLERA. 

 resembles the lamina fusca of the 



Cornea 



Sinus venosus sclerae 



Circulus arteriosus 

 major 



Conjunctival vessels 

 Recurrent artery 

 of chorioid 

 Anterior 

 ciliary 

 vessels 



Sclera 

 Chorioid 



Retina 



The lamina suprachorioidea resembles the lamina fusca of the sclera, and 

 consists of a series of fine non- vascular lamellae, each containing a delicate network 

 of elastic fibres, amongst 

 which are stellate, pig- 

 men ted cells and amoe- 

 boid cells. The spaces 

 between the laminse 

 are lined with endo- 

 thelium, and together 

 form the spatium peri- 

 chorioideale, already 

 referred to (p. 808). 



The proper tissue of 

 the chorioid consists 

 of blood - vessels and 

 numerous pigmented 

 cells, supported by con- 

 nective tissue, elastic 

 fibres, and some non- 

 striped muscular fibres. 

 Its outer part contains 

 the larger blood- vessels, 

 and is named the lamina 

 vasculosa, while its 

 inner portion is com- 

 posed of a network of 

 fine capillaries, and is 

 termed the lamina 

 choriocapillaris ; these 

 two laminae are joined 

 by a thin intermediate 

 stratum. The arteries 

 of the chorioid are de- 

 rived from the short 

 posterior ciliary vessels 

 which pierce the sclera 

 around the entrance of 

 the optic nerve, and 



form a wide-meshed FlG 682 ._ D iAGRA M OF THE CIRCULATION IN THE EYE (Leber). 



plexus in the lamina 



vasculosa. The circular muscular coats of the arteries are well developed, and 

 longitudinal muscular fibres also are present in the larger branches. The veins, 



Vessels of iris 



Vessels of ciliury process 



Suprascleral vessels 



Vena vorticosa 



Long posterior ciliary artery 

 Short posterior ciliary artery 



( Outer and 



Dinner vessels of optic sheath 



Optic nerve 



Central artery and vein of retina 



