ISSN:
1432-0878
Keywords:
Eye
;
Bird
;
Pecten oculi
;
Capillaries
;
Ultrastructure
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary The pecten oculi of the sparrow consists of capillaries, pigment cells and a superficial membrane. Because of the loose structure of the first two components broad intercellular spaces occur in the pecten. The capillary wall consists of endothelial cells and a perivascular membrane. The bodies of the endothelial cells are flattened, while the plasmalemma of both their surfaces (basal and luminal) is strongly folded and forms numerous microfolds with an average thickness of 700 Å. The height of the inner microfolds is 1.4–1.8 μm, the outer microfolds measure 1.3–1.6 μm. They lie densely packed side by side and are separated by recesses of the capillary lumen ca. 500 Å wide. Due to this the surface of the endothelial cell is increased by approximately 20-fold. The adjoining endothelial cells abut or overlap with margins, and are joined by the zonulae adherentes. Pigment cells form numerous processes and microvilli. Some rest on the capillary walls, while others penetrate the superficial membrane of the pecten or fill the intercellular spaces.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00307352
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