Polyarteritis nodosa is a systemic vasculitis of which vessels?

Polyarteritis nodosa is a systemic vasculitis of which vessels?

• A. Large veins
• B. Capillaries
• C. Medium to small arteries
• D. Lymphatics

Answer: (C)

This question tests understanding of which vessels polyarteritis nodosa primarily involves. PAN is a systemic vasculitis that targets medium-sized muscular arteries, causing transmural inflammation with fibrinoid necrosis and often aneurysm formation in renal and visceral arteries. That arterial involvement explains many clinical features and, importantly, why veins, capillaries, and lymphatics are not the primary targets in this disease. Hence, medium-to-small arteries are the characteristic vessels affected, distinguishing PAN from processes that affect capillaries or veins.

This question tests understanding of which vessels polyarteritis nodosa primarily involves. PAN is a systemic vasculitis that targets medium-sized muscular arteries, causing transmural inflammation with fibrinoid necrosis and often aneurysm formation in renal and visceral arteries. That arterial involvement explains many clinical features and, importantly, why veins, capillaries, and lymphatics are not the primary targets in this disease. Hence, medium-to-small arteries are the characteristic vessels affected, distinguishing PAN from processes that affect capillaries or veins.