Page 108 - MNU microbiology theoritical 2025

General Microbiology & Immunology (PM 401) Second level Semester 4 2024/2025

A. Inflammation

• Nonspecific response to tissue damage resulting from various causes
• Characterized by redness, heat, swelling, and pain

• Two types: Acute & Chronic

Acute inflammation

– Develops quickly and is short lived

– Is usually beneficial

– Important in the second line of defense

• Dilation and increased permeability of the blood vessels

• Migration of phagocytes

– Tissue repair

Chronic inflammation

- Develops slowly and lasts a long time

- Can cause damage to tissues

- Stages of Inflammation

1. Vasodilation: Increase in diameter of blood vessels. Triggered by

chemicals released by damaged cells: histamine, kinins, prostaglandins, and

leukotrienes. (redness and heat)

2. Enhanced capillary permeability: blood vessels dilate and become more

leaky to allow WBCs and clotting factors to enter the tissue (swelling or

edema).

3. Attraction of more phagocytes to the area (The reason why the body has

an inflammatory response).

➢ The migration of phagocytes is a multi-step process that involves

General Microbiology & Immunology (PM 401) theoretical handbook Page 97