Question

What induces the inflammatory response? What are the characteristic features of this response?

Answer 1

Several factors which all work to together to produce the cardinal signs of inflammation

Explanation:

There are 5 cardinal symptoms of inflammation:

redness
warmth
swelling
pain
fever

So let's break each symptom down and explain what is causing them:

The redness, warmth, and swelling that are characteristic of inflammation can all be grouped together as they are caused by the same factors. The most important thing to understand is that they are caused by blood leaving the circulation and seeping into the damaged/infected tissues. Three factors contribute to this: histamine (the most important inducer), prostaglandins, and bradykinin. These factors induce arteriolar vasodilation as well as capillary leakage. The end result is fresh, warm blood leaking into the interstital area, thus contributing to the warmth, redness, and swelling.

The feeling of pain comes from two factors: prostaglandin E and bradykinin. These factors increase the sensitivity of nerve receptors in the surrounding area, leading to the feeling of pain.

And finally, fever is the result of a rather complex systemic process that is not relevant here. Just understand that a cytokine known as interleukin-1 is crucial to this process, as it triggers the brain to raise the body's temperature, resulting in fever.

Hope this helps!

~AP