title: The conjunctiva and nictitating membrane of the eyelids in some reptilian species: a SEM overview.
abstract: The conjunctiva and nictitating membrane of reptilian eyelids have been studied by means of SEM. The whole surface pattern of the eyelids can be subdivided into the centrally positioned A-zone near the rims and the surrounding B-zone, including the fornix conjunctivae. The A-zone is characterized by the presence of epithelial lamellae or similar arranged cellular protrusions. All conjunctival epithelial cells demonstrate protrusions of extent morphological variety. Numerous goblet-cells occur in the B-zone and progressively increase in density in the direction of the fornix conjunctivae and the epithelial cells exhibit decreasing protrusions. The lower eyelid incorporates the discus conjunctivae, a platelike formation. It consists of dense connective tissue in which the collagen fibres stretch out orthogonally in a plywood-like manner. The nictitating membrane can be considered as a conjunctival fold near the rostral angle of the eyelids. Its bulbar surface folds in a perpendicular direction.
authors.affiliation: Institute of Anatomy, University of Münster, Germany. hiller@uni-meunster.de
authors.forename: U
authors.initials: U
authors.lastname: Hiller
mesh_terms: D000818:Animals; D003228:Conjunctiva / Q000648:ultrastructure*; D008116:Lizards / Q000033:anatomy & histology*; D008855:Microscopy, Electron, Scanning; D009541:Nictitating Membrane / Q000648:ultrastructure*; D013045:Species Specificity