from The American Heritage® Dictionary of the English Language, 4th Edition
- n. The membranous outer covering of an organ or a blood vessel.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. The outermost layer of epithelial tissue encasing a visceral organ.
from the GNU version of the Collaborative International Dictionary of English
- n. the membranous outer covering of an organ or blood vessel.
from The Century Dictionary and Cyclopedia
- n. In anatomy, any membranous structure covering an organ but not properly belonging to it (in full, membrana adventitia, adventitious membrane); specifically, the outermost of the three coats of a blood-vessel (in full, tunica adventitia, adventitious tunic), consisting of connective tissue.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. an enveloping or covering membrane or layer of body tissue
Outer layer: The outer layer the adventitia shields the artery from the rest of your body like sausage casing; it holds the artery together from the outside.
Figure 5.2 Moving Through The artery has three layers—the inner to help blood move through the artery (intima), the outer (adventitia) to protect it from the outside, plus a middle, muscular layer (media).
The histological examination showed a large increase of the connective tissue of the adventitia and of the connective tissue of the intima, but the muscular fibres were normal.
This thickening was mainly produced by an augmentation of the connective tissue of the adventitia and of the intima.
This network forms an adventitia to the bloodvessels.
This latter is composed of a few circular unstriped muscle cells a. The adventitia, similar in structure to that of an artery.
The adventitia gradually merges into the surrounding connective tissue.
The fibrous coat (tunica adventitia) is continuous at one end with the fibrous tunic of the kidney on the floor of the sinus; while at the other it is lost in the fibrous structure of the bladder.
The arteries are composed of three coats: an internal or endothelial coat (tunica intima of Kölliker); a middle or muscular coat (tunica media); and an external or connective-tissue coat (tunica adventitia).
The endothelium is supported on a membrane separable into two layers, the outer of which is the thicker, and consists of a delicate, nucleated membrane (adventitia), while the inner is composed of a network of longitudinal elastic fibers (media).