Question

Short answer:

list the stages of inflammation and briefly describe them.

Answer 1

Inflammation is part of the complex biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or irritants, and is a protective response involving immune cells, blood vessels, and molecular mediators. The function of inflammation is to eliminate the initial cause of cell injury, clear out necrotic cells and tissues damaged from the original insult and the inflammatory process, and initiate tissue repair.

Inflammation is a generic response, and therefore it is considered as a mechanism of innate immunity, as compared to adaptive immunity, which is specific for each pathogen.

The five classical signs of inflammation are heat, pain, redness, swelling, and loss of function.

Inflammation is a result of damage to body tissues and can be caused by a number of factors including trauma, repetitive use and those conditions affected by age such as Osteoarthritis.

The are three main stages of inflammation which can each vary in intensity and duration:

1. Acute -swelling stage
2. Sub-acute – regenerative stage
3. Chronic – scar tissue maturation and remodelling stage.

-During the acute inflammatory stage, there is evident redness (erythema) and swelling due to vascular changes. Exudation of cells and chemicals cause swelling and pain. A haematoma may form if there is bleeding within the tissues. Secondarily, chemical irritants are neutralized and the area is sealed off from surrounding tissues and circulation is impaired.

-The sub-acute stage is the commencement of healing and repair. Noxious chemicals are further neutralized and new capillary beds growing into the damaged areas are supported by connective tissue growth (collagen fibres) and together form granulation buds. Visible signs of inflammation start to subside and range of movement increases with pain felt at the point of tissue resistance.

-The chronic inflammatory stage is the period when tissue remodelling takes place. Signs of inflammation are absent and scar tissue is maturing. Pain is felt further into the range of movement after the tissue resistance has been reached. Maturation refers to the growth of the fibroblasts to fibrocytes and remodelling refers to the organization of and shrinking of collagen fibres along the lines of stress.