Are blood vessels organs?
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.