The cardinal sign of inflammation called rubor is mainly the result of:: (A) Decreased interstitial hydrostatic pressure, (B) Decreased vascular permeability of capillaries, (C) Increased vascular permeability of venules, (D) Vasodilation of arterioles
Answer is D. Inflammation can be defined as the reaction of vascularized living tissue to local injury. Celsus originally described four cardinal signs of inflammation: rubor (redness), tumor (swelling), calor (heat), and dolor (pain). Virchow later added a fifth sign, loss of function (functio laesa). Redness (rubor) and heat (calor) are primarily the result of increased blood flow, secondary to vasodilation of arterioles.