Assertion: blood vessel's layer | /r/MadeOf | connective tissue
Facets:
Source sentences:
text: The thick outermost layer of a vessel (tunica adventitia or tunica externa ) is made of connective tissue.
text: One more layer is the tunica externa made of connective tissue that’s mostly collagen fibers.
text: Microscopically, veins have a thick outer layer made of connective tissue, called the tunica externa or tunica adventitia.