the membranous outer covering of an organ or blood vessel
- an enveloping or covering membrane or level of body tissue
The outermost connective structure addressing of every organ, vessel, or any other construction. Including, the connective structure that encompasses an artery is known as the adventitia since it is considered extraneous to your artery.
adventitia [Tunica adventitia, Tunica externa]
Gull and Sutton asserted that in particular states of body, and more especially in the condition associated with cirrhotic kidney, such a fibrosis becomes general, running, as they alleged it does, along the adventitia of arteries and spreading to their capillaries.