What is the term for the reaction of tissue to an irritant?

The reaction of tissue to an irritant is known as inflammation. This process involves a series of biological responses that occur in the body as a defense mechanism against harmful stimuli such as pathogens, injury, or irritants. Inflammation is characterized by four main signs: redness, heat, swelling, and pain. These signs are the result of increased blood flow and immune cell activity in the affected area, allowing the body to neutralize harmful agents and begin the healing process.

In contrast, infection refers specifically to the invasion of tissues by pathogenic microorganisms, which can lead to inflammation but is not synonymous with it. Necrosis describes the death of tissues due to factors like lack of blood flow or toxic exposure, and degeneration relates to the gradual decline in the functional capacity or structure of tissue, often due to wear and tear or disease rather than a direct response to irritants. Inflammation is therefore a distinct and crucial reaction in the body’s effort to protect itself and promote repair.