Understanding Inflammation: Types, Causes & Features

• Inflammation is the body's response to injury or infection.

Types of Inflammation

• Acute inflammation is an immediate response that lasts from hours to days.
• Chronic inflammation is a prolonged response, lasting from weeks to years.

Causes of Inflammation

• Infection may be bacterial, viral, fungal, or parasitic.
• Trauma includes physical injuries like cuts, burns, or fractures.
• Autoimmune disorders occur when the immune system attacks healthy tissues.
• Toxic insults are caused by exposure to chemicals, pollutants, or radiation.

Pathological Features

• Rubor (redness) is caused by increased blood flow to the affected area.
• Tumor (swelling) is caused by the accumulation of fluid and immune cells.
• Calor (heat) is due to increased temperature.
• Dolor (pain) results from nerve stimulation and the release of pain mediators.
• Functio laesa (loss of function) is impaired tissue function.

Inflammatory Cells

• Neutrophils are first responders that primarily fight bacterial infections.
• Macrophages engulf and digest foreign particles, bacteria, and dead cells.
• Lymphocytes play a key role in adaptive immunity; these include B and T cells.
• Eosinophils are involved in fighting parasitic infections and allergic reactions.
• Basophils release histamine, contributing to allergic responses.

Chemical Mediators

• Cytokines are signaling molecules that coordinate inflammatory responses.
• Chemokines direct immune cells to sites of inflammation.
• Prostaglandins regulate pain, fever, and blood flow.
• Histamine is released during allergic reactions, causing vasodilation and smooth muscle contraction.

Consequences of Inflammation

• Tissue damage can lead to tissue destruction and scarring.
• Chronic diseases may arise contributing to conditions like atherosclerosis, diabetes, and cancer.
• Immune system dysregulation can disrupt the balance of the immune system.