Page 109 - MNU microbiology theoritical 2025

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

- Margination is the process in which phagocytes adhere to the endothelium

wall of the blood.

- Diapedesis (extravasation): Phagocytes squeeze between endothelial cells

of blood vessels and enter surrounding tissue

- Chemotaxis: reaching the site of injury

➢ Phagocytes destroy microbes, as well as dead and damaged host cells.

B. Fever

• A body temperature over 37C

• Hypothalamus acts as body’s thermostat

• Mechanisms of fever

1- When macrophages detect endotoxin produced by microbe, they release

inflammatory cytokines (interleukin–1, IL6, TNF).

o Fever-inducing cytokines are called endogenous pyrogens

o whereas microbial products are called exogenous pyrogens

2- Pyrogen Resetting of hypothalamus thermostatic set point to a higher level

(prodrome)

General Microbiology & Immunology (PM 401) theoretical handbook Page 98