When an aggressive agent enters the body, it usually lodges in some tissues. On the other hand, the white blood cells, the body’s soldiers, are located in the blood within the blood vessels. To combat the aggressive agent, these soldiers need to go to the tissue that has been invaded. Inflammation is the process in the body that enables the leukocytes to leave the vessels and go precisely towards the aggressive agent and start a fight to destroy or disable the aggressor.
For example, if we inhale something toxic or infectious, the toxin or the germ enters the lung tissue. Soon afterwards, the blood vessels in the lung dilate to allow the maximum of blood flow. Then changes take place in the capillaries lining cells that increase the permeability of the capillary walls. This change allows the white blood cells to leave the capillaries and enter the tissue. Once in the tissue, the soldiers sense the location of the aggressor via some chemicals. They move in that direction and start the processes necessary for the removal of the germ or other kinds of pathogens. This whole process is called inflammation. Numerous chemicals are involved in the inflammatory process. In the attempt to remove the foreign invader, some destructions will also happen in the host tissue. It is the price that the body pays to combat the aggressor.
Inflammation can be acute or chronic. Acute infection happens in a matter of minutes and lasting for a couple of days. It usually ends in the elimination of the invader, leaving some tissue damage on the battlefield that will be repaired. However, if the agents resist removal, and the body fails to eliminate them during the acute phase, the inflammation enters the chronic phase. Sometimes, for different reasons, the inflammation may start as a chronic one, without any preceding acute phase. It usually depends on the nature of the aggressor. It is obvious that chronic inflammation is accompanied by more destruction in healthy tissues.
Inflammation is a natural defence process of the body. However, Chronic inflammation is the underlying mechanism of many of our most common chronic diseases. We will talk more about this in other posts.
