Assertion: pericardium's heart | /r/HasProperty | cardiac muscle cells
Facets:
value: largely
type: DEGREE
Source sentences:
text: You will recall that the heart is a remarkable pump composed largely of cardiac muscle cells that are incredibly active throughout life.
text: myocardium: thickest layer of the heart composed of cardiac muscle cells built upon a framework of primarily collagenous fibers and blood vessels that supply it and the nervous fibers that help to regulate it