ISSN:
1432-0878
Keywords:
Caecal epithelium
;
Trematodes, Cercariae
;
Extracellular membranes, Membranous whorls
;
Light and electron microscopy
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary The intestinal caeca of the intraredial cercaria of Neophasis lageniformis differ in several aspects from previous descriptions of the intestinal caeca of other digenetic trematodes. The caeca are lined with a single-layered, non-syncytial epithelium with lamellate projections into the lumen. The cells are rich in glycogen particles and contain abundant granular endoplasmic reticulum. The apical cell membrane, which displays a unit membrane structure, is always covered by an external membrane of the same thickness as a unit membrane but showing no double-layered substructure. The external membrane, which is not equivalent to a glycocalyx, may continue from one cell to another. Apically on the projections the external membranes are apparently pushed out forming large, extracellular whorls, which fill up the caecal lumen. In the lumen there are also found crystal-like structures and lipid-like bodies which are suspended in a granular substance. The possible origin and function of the extracellular bodies are discussed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00306594
