The document provides an overview of inflammation, defining it as the body's local response to injury aimed at eliminating harmful agents and initiating healing. It discusses the etiology of inflammation, clinical signs such as redness, swelling, heat, pain, and loss of function, and distinguishes between acute and chronic inflammation. Both types are characterized by different durations and cellular responses, with examples of diseases associated with each type.

1. Inflammation
Archana.K

2. Concepts
Introduction
Definition
Etiology
Clinical signs of inflammation
Different types of inflammation
Mechanism of inflammation

3. Introduction
 Inflammation is a critical homeostatic process that is activated by cellular
injury regardless of the mechanism of that injury.
 Inflammation is defined as "the local response of living mammalian tissues
to injury due to any agent".
 It is a body defense reaction in order to eliminate or limit the spread of
injurious agent, followed by removal of the necrosed cells and tissues.
 Inflammation is essentially local in nature, although cellular mediators
released during inflammation may initiate systemic responses as well.
 Inflammation is the body’s attempt of self-protection; the aim being to
remove harmful stimuli, including damaged cells, irritants, or pathogens and
begin the healing process.

4.  Inflammation does not mean infection, even when an infection causes
inflammation.
 Infection is caused by a bacterium, virus or fungus, while inflammation is the
body’s response to it.
 Any injury, including an invasion by micro-organisms, causes inflammation in
the affected area.
 Inflammation, a complex reaction, results from many different conditions.
The damaged tissue releases substances that cause inflammation and that
direct the immune system to do the following:
• Attack and kill any invaders.
• Dispose off dead and damaged tissue.
• Begin the process of repair.

5. Etiology
 Agents causing inflammation
1. Physical agents: heat, cold, radiation and mechanical trauma.
2. Chemical agents : Organic and inorganic poisons. eg: arsenic, lead
3. Infective agents: Bacteria, virus and their toxins.
4. Immunological agents: Cell mediated antigen and antibody reaction.

6. Clinical signs of inflammation
 The four principal effects of inflammation are:
1. Redness (rubor)
2. Swelling (tumor)
3. Heat (calor)
4. Pain (dolor)
5. Loss of function
 They were first described by the Roman Aulus Cornelius Celsus nearly 2,000
years ago.
Redness: (rubor)
 Inflamed tissue appears red due to dilation of blood vessels in the damaged
area.
Swelling : (tumor)
 Swelling results from edema, accumulation of fluid in extravascular space.
Heat: (calor)
 Increase in temperature is detected on the skin due to increased blood flow
resulting in vascular dilation and delivery of warm blood to the part.

7. Pain: (dolor)
 Pain results partly from the stretching and distortion of tissues due to
inflammatory edema.
Loss of function:
 A well known consequence of inflammation.
 Movement of inflamed area is inhibited by pain.
 Swelling may physically immobilize the affected area.

8. Types of inflammation
 Depending on the dense capacity of the host and duration of the inflammation
it is classified in to two types.
1. Acute inflammation
2. Chronic inflammation
Acute inflammation:
 Acute inflammation is of short duration and represents early body reaction
followed by the healing.
 Examples: 1. Acute bronchitis
2. Sore throat
3. scratch/cut on the skin
4. Acute appendicitis
5. Acute Dermatitis
6. Acute Tonsillitis
7. Acute infective meningitis
8. Acute sinusitis

9. Chronic Inflammation:
 Chronic inflammation is for longer duration.
 It occurs either prolonged presence of acute inflammation due to causative
agents or stimulus that induces chronic inflammation from beginning.
 Features of chronic inflammation is presence of chronic inflammatory cells
such as lymphocytes, plasma cells and macrophages.
 Macrophages are derived from monocytes, walls of blood vessels and in loose
connective tissue.
 They interact with lymphocytes to facilitate antibody production.
Example diseases:
1. Asthma
2. Chronic peptic ulcer
3. Tuberculosis
4. Rheumatoid arthritis
5. Chronic sinusitis
6. Chronic active hepatitis