The primary role of arterial anastomoses is to:

• A. Provide collateral circulation, offering alternative routes if one artery is blocked
• B. Increase arterial resistance
• C. Reduce blood flow to tissues
• D. Drain blood from tissues

Answer: (A)

Arterial anastomoses create collateral pathways that provide alternative routes for blood flow if a primary artery becomes blocked. This redundancy helps keep tissues perfused and oxygenated during occlusion, reducing the risk of ischemia. By connecting arteries, these vessels can distribute flow more evenly and maintain local pressures when demand or a single pathway is compromised. The other options don’t fit because increasing resistance would hamper flow, reducing rather than preserving perfusion; reducing blood flow to tissues isn’t the job of these connections; draining blood from tissues is a venous function, not arterial.