During development, the scleral ossicles are foreshadowed by a ring of papilliform thickenings in the conjunctival epithelium. The conjunctival papillae appear during the eighth day. They correspond in number and location with the bones which subsequently develop in the mesenchyme underlying them.

2018年12月8日 · The scleral cartilage is situated deeper within the sclera. In reptiles, it takes the form of a cartilage cup that lines the retinal pigmented epithelium externally (Fig. 2). The scleral cartilage is absent in snakes, and has been secondarily lost within some groups.

2006年2月22日 · Scleral papillae and scleral ossicles arise sequentially and in the same strict order. The first sign of ossification is present at day 11–12 (HH stage 37–38), preceded by a prominent preossicular condensation (at day 10, HH stage 36).

2018年4月1日 · The results of this study provide considerable insight into the spacing pattern of scleral papillae. A reaction-diffusion mechanism explains the ability of scleral papillae to maintain their even distribution regardless of differences in numbers among species or between left and right eyes in the same individual.

2019年10月30日 · The papillae in the chicken embryonic eye, described as scleral papillae in the well-known Hamburger and Hamilton (1951) staging table, are one of the key anatomical features used to stage reptilian (including bird) embryos from HH30-36. These papillae are epithelial thickenings of the conjunctiva and are situated above the mesenchymal sclera.

We have used a polyclonal antibody against tenascin (a 240 kDa extracellular matrix glycoprotein) and indirect immunofluorescence to investigate the distribution of tenascin in cryostat sections of the chick sclera during the six stages of scleral papilla development (Murray, 1943) and formation of membrane bone anlagen (mesenchymal ...

The membrane bones or scleral ossicles (usually 14 in number) form an imbricated ring surrounding the corneal limbus. During development, the scleral ossicles are foreshadowed by a ring of papilliform thickenings in the conjunctival epithelium. The conjunctival papillae appear during the eighth day.

Eyes of early embryonic chicks possess 14 scleral papillae, derived from the conjunctival epithelium and present as transient structures between seven and 11 days of incubation. These papillae induce the formation of the 14 scleral ossicles, which develop in the adjacent, neural crest-derived ectome …

2012年5月1日 · These papillae are small, transient clusters of epithelial cells that form outgrowths of the conjunctival epithelium (Coulombre and Coulombre, 1962). Despite the fact that these papillae form from the conjunctiva, they are commonly referred to as ‘scleral’ papillae (Hamburger and Hamilton, 1951).

The papillae in the chicken embryonic eye, described as scleral papillae in the well‐known Hamburger and Hamilton (1951) staging table, are one of the key anatomical features used to stage ...