Retinal Pigment Epithelial Fine Structure in the Red-Tailed Hawk (Buto jamaicensis)
| Autor: | Charlie R. Braekevelt |
|---|---|
| Rok vydání: | 1992 |
| Předmět: |
Male
Biology Endoplasmic Reticulum Birds chemistry.chemical_compound Polysome Organelle medicine Animals Pigment Epithelium of Eye Melanosome Cuboidal Cell General Veterinary Tight junction Retinal General Medicine Anatomy eye diseases Epithelium Cell biology Microscopy Electron Cell nucleus medicine.anatomical_structure chemistry Female sense organs |
| Zdroj: | Anatomia, Histologia, Embryologia: Journal of Veterinary Medicine Series C. 21:48-56 |
| ISSN: | 1439-0264 0340-2096 |
| DOI: | 10.1111/j.1439-0264.1992.tb00318.x |
| Popis: | Summary As part of a comparative morphological study, the fine structure of the retinal epithelium (RPE), choriocapillaris and Bruch's membrane (complexus basalis) has been studied by electron microscopy in the red-tailed hawk (Buteo jamaicensis). In this species the RPE consists of a single layer of low cuboidal cells which display numerous basal (scleral) infoldings and extensive apical (vitreal) processes which interdigitate with photoreceptor outer segments. These epithelial cells are joined laterally by a series of basally located tight junctions. Internally SER is the most abundant cell organelle while only small amounts of RER are present. Polysomes are however abundant as are mitochondria. The RPE cell nucleus is large and vesicular. Melanosomes are mainly located in the apical processes of the RPE cells in light-adaptation. Myeloid bodies are large and numerous in light-adaptation and often show ribosomes on their outer border. Bruch's membrane (complexus basalis) shows the typical pentalami-nate structure noted in most vertebrates but with only a poorly defined central elastic layer. The endothelium of the choriocapillaris is very thin facing the RPE but is only moderately fenestrated. The choriocapillaris in this species is unusual however in that many of the fenestrae show a double-layered diaphragm. |
| Databáze: | OpenAIRE |
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