Inflammation plays a protective role in our bodily tissue, it can last from a few minutes to a few years. With inflammation comes different processes such healing and sometimes infection. This blog is my understanding of these processes after going through a couple of articles, textbooks and journals.
CLASSIFICATION OF INFLAMMATION
There are two types of inflammation, acute inflammation and chronic inflammation. ” Acute and chronic inflammation are crudely based on duration of the lesion and histological appearances”1. M Bezabeh (2004) . The causative agent and amount of damage caused are the sources of the classification of inflammation. ” Classification can be based upon the nature of the inflammatory exudate, the duration of the inflammation and the site of inflammation.”2. Rippey (1994) . The inflammatory exudate replaces damaged area with the exudate components to steer away bacteria that might cause infection. The duration of the inflammation is dependent on type of inflammation, acute inflammation takes less time as compared to chronic inflammation, which can take years.
The video above gives an overall view of acute and chronic inflammation.
I remember how i smashed my finger with a door, not only once but on several occasions. OUCH!!! The pain was excruciating and unbearable. With the pain ( Dolor) came a sudden rush of heat ( Calor), which I quickly tried to ease by running cold water on the finger. I can’t say that helped, instead the pain became even worse. This was followed by redness, swelling ( Tumor) and loss of function. With the knowledge I have now gained about acute inflammation, the signs that i mentioned are clinical signs of inflammation. According to M. Bezabeh redness is due to dilation of small blood vessels in damaged tissue. Heat is due to increased blood flow (hyperemia) due to regional vascular dilation. Swelling is due to accumulation of fluid in the extra-vascular space, which in turn is due to increased vascular permeability. Pain partly results from stretching and destruction of tissue due to inflammatory oedema, chemicals of inflammation – bradykinins, prostaglandins and serotonin ( induce pain ). Loss of function is due to inhibition of inflammed area by pain and severe swelling.
figure 1. This image shows am inflammed finger, swelling and redness are visible
A moderate measure of inflammation is beneficial in demolishing infectious bacteria and healing after an injury. If the measure of inflammation is increased and the response doesn’t cease, chronic inflammation occurs. ” It acts like a slow- burning fire, continuing to stimulate pro-inflammatory immune cells when they may not be needed”. 3.M. Pick (2011). My mother was diagnosed with rheumatoid arthritis a couple of years ago, attacking mainly the joints of the hands, wrist and knees. ” The inflammatory process primarily affects the linning of the joints, or affect other organs. Rheumatoid arthritis is believed to result of a faulty immune response” 4. This can cause permanent joint destruction and deformity. Chronic infammation is an example of imbalance in homeostasis. The increased inflammatory response exceeds threshold causing the body to manifest signs and symptoms which is its a way of restoring balance. This results in the designated type of chronic inflammation, which may be ‘non-specific’ or ‘granulomatous’.
figure 2. this image shows the mechanisms of acute and chronic inflammation in asthma.
Healing and repair
You get a cut, hemorrhage takes place and ceases eventually, it is then followed by the signs and symptoms of inflammation ( as mentioned above ). As time passes you notice the cut begginning to dry up, getting scabby and brown in colour. This occurs during the process of healing, it is one example in many other types of healing. The scabby layer protects the wound, while the damaged skin is healing and forming new beneath it. The healing process may involve resolution, regeneration and organisation. ” resolution – restore normal structure and function of tissue. regeneration – loss of normal architecture. organisation – replacement of lost tissue with granulation tissue.” Rippey (1994).
Tissue damage = inflammation – removal of dead tissue & injurious agent = replacement by fibrous tissue ( scarring) or specialised tissue ( regeneration) = HEALING
Above is a summary of the process of healing. The healing process is determined by 3 cell types, Labile cells, Stable cells and Permanent cells.
figure 3. This image shows the process of wound healing.
Infection and some infectious diseases
My basic understanding of an infection is that, its the contamination or entry of pathogenic micro organisms in body tissue. These micro organisms multiply in the tissue causing a state of disease. Infection can spread in many ways, an example can be direct spread during coughing, the micro organism can escape and infect an0ther person.
Above is a video about the history of infection, causes and control.
Inflammation, healing and infection are inter-linked. The ultimate goal of inflammation is repairing tissue and eliminating the causative agent, which in turn achieves homeostasis. Inflammation can also result due to the presence of infectious microbes. Healing repairs the damage in tissue, assembling and forming new tissue for protection against pathogens.
1. M Bezabeh, General pathology, 2004, Jimma University, pg 34,35
2. JJ Rippey, General Pathology, 1994, Witwatersrand University, pg 142, 155
3 .M Pick, what is chronic inflammation, 2011,http://www.womentowomen.com/inflammation/whatischronicinflammation.aspx. 8 April 2013
4. http://www.cdc.gov/arthritis/basics/rheumatoid.htm#. 8 April 2013