Textbook of normal histology: including an account of the development of the tissues and of the organs . rectly into the ground-substance of the sclera ; in consequence ofthe rearrangement of the tissue-elements of the two structurestaking place soonest in the superficial planes of the cornea, the lineof transformation becomes oblique, thereby producing an apparentoverlapping of the sclera in front, and a corresponding extension ofthe cornea behind. The posterior elastic membrane, on reaching the corneal mar-gin, splits up into a number of stiff homogeneous fibres, many ofwhich become attached
Textbook of normal histology: including an account of the development of the tissues and of the organs . rectly into the ground-substance of the sclera ; in consequence ofthe rearrangement of the tissue-elements of the two structurestaking place soonest in the superficial planes of the cornea, the lineof transformation becomes oblique, thereby producing an apparentoverlapping of the sclera in front, and a corresponding extension ofthe cornea behind. The posterior elastic membrane, on reaching the corneal mar-gin, splits up into a number of stiff homogeneous fibres, many ofwhich become attached to the base of the iris and constitute the liga-mentum pectinatum iridis. By the union of the processes fromthe iris and Descemets membrane with the elastic fibres derivedfrom the anterior attachment of the ciliary muscle and a few bandsfrom the sclera, a reticulum of thin trabeculae is formed, whichoccupies the angle between the cornea and the iris. This spongytissue constitutes an annular mass enclosing a system of intercom-municating cavities, the spaces of Fontana. These clefts, lined Fig. Section through irido-corneal angle of human eye, highly magnified : a, substantia propriaof cornea; b, posterior limiting membrane, splitting at corneal margin into delicate lamella(rf) ; c, endothelium continued over iris (z) ; f, elastic lamellae separating Schlemms canal (S)from spaces of Fontana (s, s) and giving attachment to fibres of ciliary muscle (h). by an imperfect layer of endothelium, are more conspicuous in theeyes of some of the lower animals (horse; ox, pig, sheep), wherethey are far better developed than in man. Within the sclera, close to its inner border and the corneal juncture, THE EYE AND ITS APPENDAGES. 351 lies a flattened annular channel, the canal of Schlemm ; theinner wall of this canal is formed by intersecting delicate lamellaewhose loose disposition suggests an incomplete isolation of thechannel from the adjacent spaces of Fontana. The nature of theca
Size: 1922px × 1300px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorpiersolgeorgeageorgea, bookcentury1800, bookdecade1890
