Assertion: pericardium's layer | /r/HasProperty | main
Facets:
Source sentences:
text: The pericardium is made up of two main layers: a tough external layer known as the fibrous pericardium, and a thin, internal layer known as the serous pericardium (to overextend the orange metaphor, the outer peel could be thought of as the fibrous layer, with the inner white stuff being the serous layer).