Assertion: pia mater | /r/HasProperty | inner layer
Facets:
Source sentences:
text: There are three layers: the dura mater (outer), arachnoid membrane (middle) and the pia mater (inner layer).
text: The three layers of meninges are the dura mater (tough and outer), arachnoid mater (middle layer), and pia mater (inner layer).