Histology of the fresh-water mussel heart with reference to its physiological reactions

✍ Scribed by Hurley Lee Motley

• Publisher: John Wiley and Sons
• Year: 1933
• Tongue: English
• Weight: 741 KB
• Volume: 54
• Category: Article
• ISSN: 0362-2525
• DOI: 10.1002/jmor.1050540210

✦ Synopsis

Abstract

The anatomical isolation of the auricles from the ventricle in hearts of fresh‐water mussels representing nine North American species has been confirmed. The muscle fibers in these hearts without exceptions were found to be of the smooth, unstriated type. Bundles of these fibers loosely interwoven, form the thin, delicate, heart wall, which contains many sinus‐like spaces. The outside portion of the heart wall exposed to the pericardial fluid is covered with a definite epicardium composed of a single, dense layer of epithelial and scattering mucous cells. The inside of the heart cavity has no endocardium, the muscle fibers being in direct contact with the blood. No special conduction tissue, nerves or ganglia were found in the heart wall. Correlations of these anatomical and histological findings with the physiological reactions of the living heart in situ are made, and the mechanical and chemical control of the heart discussed.