An electron microscopic study on the muscle cells and nerve fibres in the digestive gland of the snail Cryptomphallus aspersa
Abadía-Fenoll, F.; Ríos, A.; Almendros, A.; Navascués, J.
Zeitschrift für Mikroskopisch-Anatomische Forschung 96(5): 873-884
1982
ISSN/ISBN: 0044-3107 PMID: 7168245 Document Number: 185067
An electron microscopic study of the muscle cells and the nerve fibers which can be found between the connective tissue of the digestive gland of C. aspersa is given. The muscle cells are smooth and are located immediately below the basal lamina of the secretory epithelium or in more central zones of the connective tissue of the gland. Thin and thick myofilaments can be found in the sarcoplasm. The thin ones have a diameter of .apprx. 5 nm; the thick ones vary in diameter between 15-65 nm. The myofilaments of 15 nm might belong to a 3rd type. Nerve fibers can be found in central zones of the connective tissue of the digestive gland, at the base of the glandular tubules and within the secretory epithelium. In these fibers it is characteristic to find a large number of granules, of a diameter between 80-250 nm, surrounded by a membrane, the content of which varies in density. Small clear vesicles of 40-70 nm in diameter can also be observed. Occasionally granules, which fuse their membranes thus mixing their content, can be detected.