Are blood vessels classified as organs? Organs compose of 2 or more tissues and perform a certain function. Blood vessels have 3 different tissues and perform a function (transport blood), yet I do not see them being identified as an organ. Why is this? Are they organs? Or do they hold their own classification?
I don't know if they are classified as organs, but basically, blood vessels match the criteria for being organs.
Quoting SIU School of Medicine:
Blood vessels are basically tubular organs found within other organs.
Biology Reference states the same:
Even the glands within the integument can be considered organs; any gland is primarily secretory epithelium surrounded by connective tissue for support and protection. Likewise, the blood vessels and nerves in these organs are organs unto themselves.
Yes blood vessels can be called as organs. They are part of organ system. By definition an organ is one which is made of different tissues and contributes with other organs to a specific function in the body. Here blood vessels are made of different tissues like smooth muscle, epithelial tissue, elastic tissue etc.