ISSN:
0362-2525
Keywords:
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Medicine
Notes:
The hepatopancreatic caeca of the freshwater amphipod Gummarus minus are four tapered blind pouches lined with a simple columnar epithelium bearing an apical surface of regular microvilli and resting on a basement membrane. This epithelium is enclosed by a tonic, striated muscularis. Each caecum consists of three regions. The distal zone is formed of embryonic cells having a high nuclear to cytoplasmic ratio and giving rise to the other cell types. The second or differentiation zone consists of regular tall columnar cells of two morphological types:(1) light staining R-cells which have a large number of lipid droplets and few Golgi bodies; (2) basophilic F-cells which have numerous distended Golgi bodies. The more proximal secretory zone forms the majority of each diverticulum. This mature zone is formed from R-cells and large, basophilic, vacuolated B-cells which differentiate from F-cells. The secretory cell sequence appears to be E-cell - F-cell - B-cell with secretion being apocrine in nature. The exact relationship of Rcells to the other cell types is questionable, but the R-, F - and B-cells all appear to be able to absorb and store nutrients. Within the Malacostraca the hepatopancreatic epithelium of Amphipoda more closely approximates that of Decapoda than that of the Isopoda.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jmor.1051490307
