. Cunningham's Text-book of anatomy. Anatomy. EEFBACTING- MEDIA OF THE EYE. 819 EEFEACTING MEDIA. Corpus Vitreum.—The vitreous body is a transparent, jelly-like substance situated between the crystalline lens and the retina, and occupying the posterior four-fifths of the bulb of the eye (Fig. 677). In front it presents a deep concavity, the hyaloid fossa ( fossa patellaris), for the reception of the posterior convexity of the lens. It is enclosed within a thin transparent membrane, the membrana hyaloidea, which is in contact with the membrana limitans interna of the retina, and is adherent
. Cunningham's Text-book of anatomy. Anatomy. EEFBACTING- MEDIA OF THE EYE. 819 EEFEACTING MEDIA. Corpus Vitreum.—The vitreous body is a transparent, jelly-like substance situated between the crystalline lens and the retina, and occupying the posterior four-fifths of the bulb of the eye (Fig. 677). In front it presents a deep concavity, the hyaloid fossa ( fossa patellaris), for the reception of the posterior convexity of the lens. It is enclosed within a thin transparent membrane, the membrana hyaloidea, which is in contact with the membrana limitans interna of the retina, and is adherent to it at the entrance of the optic nerve. The portion of the membrana hyaloidea in front of the ora serrata is thickened and strengthened by radial fibres, and is termed the zonula ciliaris. Situated behind the ciliary body, the zonula is radially folded and presents a series of alternating furrows and elevations. The ciliary processes are received into, and are firmly adherent to, the furrows, with the result that, if removed, some of their pigment remains attached to the zonula. The elevations of the zonula are not attached to the interciliary depressions, but are separated by a series of lymph spaces named the recessus camerae posteriores; these may be regarded as diverticula of the posterior chamber with which they communicate. As the zonula approaches the equator of the lens it splits into two chief layers, viz.: (a) a thin posterior lamina, which lines the hyaloid fossa; and (b) a thicker anterior layer, termed the suspensory ligament of the lens (Fig. 677), which blends with the front of the lens capsule a short distance from the equator of the lens. Scattered fibres of this ligament are also attached to the equator itself and to the regions immediately anterior and posterior to it. By this suspensory ligament the lens is retained in position, and its con- vexity varies inversely with the degree of tension of the ligament. The radial fibres of the ciliary muscle, by p
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectanatomy, bookyear1914
