ACCESSORY EYE STRUCTURES
THE EYELIDS:
The eyelids develop as the fold of surface ectoderm above and below the developing
cornea. As they grow, they grow, they become united with each other at about the third
month of intrauterine life. The lids remain fused until about the fifth month, when they start to
separate. Separation of the eyelids is complete by the seventh month. While the lids are
fused, a close space, the conjunctival sac, exists Infront of the cornea. The mesenchymal
core of the lids forms the connective tissue and tarsal plates. The orbicularis oculi muscle is
formed from the mesenchyme of second pharyngeal arch. Which invades the eyelids and is
supplied by the seventh cranial nerve.
The eyelashes develop as epithelial buds from the surface ectoderm. The arise first in
the upper lid and are arranged in two or three rows, one behind the other. The ciliary glands
of Moll and Zeis grow out from the ciliary follicles. The tarsal glands(meibomian glands)
develop as columns of ectodermal cells from the lid margins.
THE LACRIMAL GLAND:
THE EYELIDS:
The eyelids develop as the fold of surface ectoderm above and below the developing
cornea. As they grow, they grow, they become united with each other at about the third
month of intrauterine life. The lids remain fused until about the fifth month, when they start to
separate. Separation of the eyelids is complete by the seventh month. While the lids are
fused, a close space, the conjunctival sac, exists Infront of the cornea. The mesenchymal
core of the lids forms the connective tissue and tarsal plates. The orbicularis oculi muscle is
formed from the mesenchyme of second pharyngeal arch. Which invades the eyelids and is
supplied by the seventh cranial nerve.
The eyelashes develop as epithelial buds from the surface ectoderm. The arise first in
the upper lid and are arranged in two or three rows, one behind the other. The ciliary glands
of Moll and Zeis grow out from the ciliary follicles. The tarsal glands(meibomian glands)
develop as columns of ectodermal cells from the lid margins.
THE LACRIMAL GLAND:
