title: The ultrastructure of the heart of Oniscus asellus L. and Asellus aquaticus L (Crustacea, Isopoda).
abstract: The endocardium of Oniscus asellus L. and Asellus aquaticus L. consists of lipid cells. The epicardium consists of a layer of cells with a vesiculated cytoplasm covered by a thick extracellular fibrous sheet. The myocardium is a single layer of cells, the sarcolemma invaginates at Z disc level forming transverse tubules, and longitudinal tubules branch off from these. At the A-I level longitudinal tubules from transverse systems, which form couplings with the sarcoplasmic reticulum. The sarcoplasmic reticulum appears as perforated sheets enveloping the myofibrils. Two types of nerve terminal are found: one is embedded in a myocardial cell process, the other lies in a myocardial cell depression. They contain clear and dense-cored synaptic vesicles.
mesh_terms: D000818:Animals; D003445:Crustacea / Q000648:ultrastructure*; D003896:Desmosomes / Q000648:ultrastructure; D004699:Endocardium / Q000648:ultrastructure; D006321:Heart / Q000294:innervation; D008055:Lipids / Q000032:analysis; D008854:Microscopy, Electron; D008929:Mitochondria, Heart / Q000648:ultrastructure; D009206:Myocardium / Q000648:ultrastructure*; D009210:Myofibrils / Q000648:ultrastructure; D009940:Organoids / Q000648:ultrastructure; D012519:Sarcoplasmic Reticulum / Q000648:ultrastructure
chemical_list: D008055:Lipids