muscular part of interventricular septum (of heart)

mus·cu·lar part of in·ter·ven·tric·u·lar sep·tum (of heart)

[TA] the thick muscular portion that comprises most of the interventricular septum of the heart. Synonym(s): pars muscularis septi interventricularis (cordis) [TA], septum musculare ventriculorum