collateral circulation

(physiology) The circulation established for an organ or a part of an organ through the intercommunication of blood vessels when the original direct blood supply is obstructed or abolished.

Collateral circulation refers to the development of new branches of blood vessels. Regular, vigorous aerobic exercise may stimulate the formation of new branches of the coronary arteries. This may offset the effects of a thrombosis. If one of the coronary arteries becomes blocked, the new vessels can provide the blood with an alternative pathway to maintain the supply of oxygen and nutrients to the heart. Good collateral circulation may also accelerate recovery from a heart attack.

Development of alternative routes in the circulatory system. It has been suggested that new blood vessels formed as a response to regular aerobic exercise may take over normal coronary blood circulation after a coronary thrombosis reduces blood flow to heart muscle.

Circulation maintained in small anastomosing vessels when the main artery is obstructed.