The body is designed to defend itself against invading bacteria, and infection. The skin and mucous membranes are the first line of defence, the invasion of foreign bacteria can pass this first line of defence and immediately triggers the second line of defence. The second line of defence is the inflammatory response (McCance & Huether, 2009). The mechanism of the inflammatory response is to protect the injured site by killing the agent responsible, limiting its effects on the rest of the body and initiating the healing process (Porth, 2007).
According to Botwinski (2001), during infection bacteria grow and divide, and release potent toxins that cause damage to the body’s cells. These toxins trigger the initiation of the inflammatory response. The changes that occur are initiated by the interactions between bacterial products and inflammatory mediators. Inflammatory mediators are chemicals that are released by protective cells or plasma when harmful agents invade the body. Inflammatory mediators include histamine, prostaglandins, and leukotrienes (Kumar, Abbas, Fausto, Robbins, & Cotran, 2005).
The main cells involved are the mast cells and are located in connective tissue in close contact with blood vessels. Mast cells play a key role in the inflammatory response, when stimulated by infection they release a potent substance called histamine. When histamine leaks into the tissues it causes changes in the surrounding blood vessels. The two changes that occur in the blood vessels is blood vessel dilation and increased capillary permeability. The changes are designed to maximise the movement of plasma proteins and circulating cells out of the blood flow and into the site of infection (McCance & Huether, 2009).
At the onset of injury the histamine that is released causes the blood vessels at the site to constrict for a short time then dilate (Nair, 2009). This widening of the blood...