The outermost layer of a blood vessel, composed mainly of fibrous tissue. [ ISBN:0073040584 Wikipedia:Tunica_externa_(vessels) ]
术语信息
- NCIT:C33818
- BTO:0002010
- SCTID:61066005
- Wikipedia:Tunica_externa_(vessels)
- EMAPA:36299
- UMLS:C0225342 (ncithesaurus:Tunica_Adventitia)
The outermost layer of a blood vessel, surrounding the tunica media. It is mainly composed of collagen. The collagen serves to anchor the blood vessel to nearby organs, giving it stability[Wikipedia:Tunica_externa_(vessels)].
TODO - note terminological problems. WP says tunica external layer of blood vessel. FMA says tunica externa = adventitia, and is FMA adventitia covers other kinds of vessels. Here we opt for a lengthier name that attempts to disambiguate. There is no precise FMA equivalent, as FMA has tunica externa of arteries, veins, genital ducts etc as siblings