What are the four cardinal signs of inflammation.
- • Erythema (rubor).
- • Warmth (calor).
- • Swelling (tumor).
- • Pain (dolor).
What are the underlying mechanisms responsible for the signs of inflammation?
Local arteriolar dilation produces the erythema and warmth. Permeability increases in the postcapillary venules, allowing vascular fluid to leak into the surrounding tissue to produce swelling (edema).
Pain is a result of the action of numerous inflammatory mediators and inflammatory cell-derived products on local nerves. Note that these symptoms and signs are the result of innate immune system activation.