This anatomical study demonstrates that false tendons are normal structures containing Purkinje fibers and non-myelinated nerve fibers in most mammals, supporting their role in the cardiac conduction system.
Should not alter clinical practice; leaves open functional role in human conduction system.
False tendons in the heart of several mammals were investigated by light and electron microscopies. False tendons were recognized macroscopically as chordal structures in the inner surface of the ventricles in the cow, pig, monkey, dog and rabbit.The outer surface of false tendons were covered with the same endothelial cell layer as the endocardium. Under the cell layer, there was thick connective tissue whose center was occupied by several bundles of Purkinje fibers. Among Purkinje fibers, thin connective tissue was present, in which small vessels and non-myelinated nerve fibers were observed. False tendons were identified in rats by light microscopy, but they were not found in mice. Purkinje fibers in false tendons varied among species. In artiodactyla, Purkinje fibers were larger and had fewer cell organella than those of other animals. Three types of intercellular junctions, desmosomes, intermediate junctions and gap junctions (nexus), were observed. Nexuses were often observed. Nerve fibers in the false tendons were all nonmyelinated. These nerve fibers only passed through the false tendons, and nerve endings were not found. Nerve cell bodies were not found either.From these results, the roles of false tendons in heart conduction were discussed.
No takes yet. Share an insight, caveat, or question.
Tetsuhiro TAKAGI (1986) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: