In medicine,<unk> , also vessel<unk>  and blood vessel<unk> , is the growth of a blood vessel or several blood vessels that serve the same end organ or vascular bed as another blood vessel that cannot adequately supply that end organ or vascular bed sufficiently. Coronary<unk>  is considered a normal response to hypoxia and may be induced, under some circumstances, by exercise. It is considered to be protective. Collateral or anastomotic blood vessels also exist even when blood supply is adequate to an area, and these blood vessels are often taken advantage of in surgery. Some notable areas where this occurs include the abdomen, rectum, knee, shoulder, and head.
Collateralization
Emasculation
Venous cutdown
Vascular recruitment
Clot retraction
Exeresis
Solvent drag
Renal compensation