Inflammation Definition - What Is Inflammation ?

What is inflammation?

Inflammation is a reaction of the body of damage to tissue or to external stimuli. This can be done by a microbial stimulus (bacteria, viruses, fungi), chemically (irritants etc.), physically (heat, ionizing radiation, UV radiation, etc.), but also be the result of an autoimmune response of the body such as under more rheumatism may occur. An inflammation is the purpose of removal of the injurious agent and the repair of the damage.

There sometimes is a tendency to inflammation and infection by bringing together, but not all infections accompanied by inflammation and not all infections are caused by infection. Thus, a sterile inflammation is an inflammation that is not caused by an organism (for example, but due to mechanical overload, such as bursitis in the spectrum of RSI).

Phases of inflammation

If inflammation can be distinguished several phases, namely:

• Hyperemia: increased blood flow. Hyperemia is caused by vasodilating substances (vasoactive mediators), of which histamine and bradykinin are the most important. On the venous side (the side of the vein) of the capillaries and results in an increased blood flow through the vascular dilatation is called the "flow" (flow rate) is reduced from the blood. Because there is more blood in the inflamed area, the tissue will be colored red and hot.
• Exudation: egress of fluid from the bloodstream as a result of an increased permeability (permeability) of the vessel wall of the capillaries. This takes place under the influence of histamine and bradykinin, which are thus not only for hyperaemia, but also ensure exudation. The gaps between the endothelial cells become larger by the vasoactive mediators and also the hydrostatic pressure in the capillaries increases, allowing more moisture to leave the blood vessels than normal. Because of the increased permeability proteins also leave the bloodstream, so that the oncotic pressure and thus reduces the reabsorption at the end of the capillaries. This means that more moisture is left in the inflamed tissue, which is called inflammatory edema. More tissue fluid means that there is a swelling occurs at the ignition: tumor.
• Diapedesis or infiltration of leukocytes (white blood cells) from the bloodstream at the location of the inflammation. As the first steps granulocytes off (after 24-48 hours), and then the monocytes or macrophages and plasma cells. This is done under the influence of certain substances (cytokines), released by endothelial cells and cells at the site of inflammation (or damaged bacteria own cells). The leukocytes into the inflamed tissue care for phagocytosis and degradation of dead cells and pathogens. There may be a specific or non-specific reaction of the leukocytes. Granulocytes, at an inflammation especially neutrophils, and macrophages take care of the non-specific defense system and lymphocytes including plasma cells, are involved in reaction with the aid of specific antigen recognition. In an inflammation are thus different types of leukocytes into the tissue engaged thereby, therefore, there is an increased cellular activity. This has as a result an increased energy consumption and heat production in the inflamed tissue. This can be seen as one of the five ignition characteristics, namely calor.
• Proliferation of fibroblasts, among other things for the purpose of regeneration and recovery of the fabric. Redness may also occur in this phase takes place when under the influence of growth factors proliferation of blood vessels in the tissue. This gives the healing tissue, called granulation tissue, a red aspect.

Sometimes the diseased tissue can be restored to its original state, but sometimes that is not possible because the tissue has no regeneration capacity, or because the regeneration capacity is not sufficient to restore all the damage. In that case, the damaged tissue will be replaced by connective tissue which can be seen as an scar. The formation of scar tissue after healing of an inflammatory response is thus dependent on the tissue regeneration, which is determined by the type of cells. Labile cells (including the epithelial cells) divide continuously and therefore have a great capacity for regeneration. Stable cells (including endothelial cells, smooth muscle cells and liver cells), parts not normally, but in case of damage of surrounding tissue they will come up in the cell cycle. These cells therefore also have a good capacity to regenerate. Permanent cells (including neurons and striated muscle cells of the skeletal and heart) can not divide and have therefore no capacity to regenerate. In these cells will take place in case of damage so replacement of original tissue in connective tissue, which can lead to loss of function (functio laesa).

The pain (dolor) which occurs at an inflammation is caused by two factors. Firstly, there is a localized swelling due to the inflammatory edema. The swelling will mean that there is pressure being applied to the inflamed and the surrounding tissue, and as a result pain receptors are stimulated. In addition, also ensure the substances bradykinin and PGE2 for pain. Bradykinin, already mentioned as a substance that causes hyperemia and exudation, allows for the stimulation of sensory receptors. PGE2 prostaglandins, or other metabolites of arachidonic acid. Arachidonic acid itself is a component of the phospholipids contained in the cell membrane. In an arachidonic acid by leukocytes inflammation can be converted into different metabolites called eicosanoids together, under the influence of inflammatory mediators. Eicosanoids act as bradykinin on sensory receptors, thereby registering pain. The loss of function can be caused not only by replacement of original tissue by connective tissue. During the ignition will not be used to the inflamed area, or in order to prevent pain, or because it is not possible by the swelling. Also, a combination of the two is of course possible.

Inflammation treatment

Inflammation can be controlled with anti-inflammatory agents such as corticosteroids. Often these are already applied before the cause of the ignition is off, in order to take the symptoms (including pain) away.