Assertion: vein's blood vessel | /r/MadeOf | the tunica adventitia
Facets:
Source sentences:
text: The basic overall structure for veins and arteries is including the tunica intima, they have an additional two tunics; tunica media (middle layer) is the region where the blood vessels consist of smooth muscle and elastin fibres and the tunica adventitia (outer layer) is mainly composed of collagen fibres.