Assertion: membrane's surface | /r/AtLocation | a basement membrane
Facets:
Source sentences:
text: The free surface of epithelial tissue is usually exposed to fluid or the air, while the bottom surface is attached to a basement membrane.
text: The free surface of epithelial tissue is usually exposed to fluid or the air, while the bottom surface is attached to a basement membrane.
text: The bottom surface of endothelium is attached to a basement membrane, while the free surface is usually exposed to fluid.