The Mouse Adult Gross Anatomy Ontology and Mammalian Phenotype Ontology are downloaded weekly from the Mouse Genome Informatics databases at Jackson Laboratories (ftp://ftp.informatics.jax.org/pub/reports/index.html). For more information about these ontologies, see the MGI Publications Page at http://www.informatics.jax.org/mgihome/other/publications.shtml.
any structural anomaly of the involuntary muscle comprising the myocardium of the heart and the walls of the pulmonary veins and superior vena cava; cardiac muscle is striated and multinucleate, and the cardiomyocytes branch and are joined to one another via intercalated discs
Comment:
Do not confuse cardiac muscle tissue with the myocardium. Myocardium consists primarily of cardiac muscle but these structures are not identical. Cardiac muscle tissue also exists outside the heart so this term has not been made a child of heart myocardial layer directly.