Assertion: blood vessel's layer | /r/HasProperty | smooth muscle
Facets:
value: primarily
type: DEGREE
Source sentences:
text: The middle layer, the tunica media, is primarily smooth muscle and is usually the thickest layer.
text: Arteries are made up of several layers, which include a layer of connective tissue, some smooth muscle-- which again, can contract or relax to manage blood flow and pressure-- and it also has a layer of endothelium.