Page 110 - MNU microbiology theoritical 2025

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

2- Endogenous pyrogen (cytokines) causes the hypothalamus to secrete

prostaglandin

3- prostaglandin reset hypothalamus thermostatic set point to a higher level which

in turn causes fever as a systemic reaction

▪ Chills associated with fever are due to the reduced blood flow of constricted

vessels

▪ Decrease in IL-1 production results in the body’s temperature returning to normal

Benefits of Fever

• Inhibited pathogen growth

• Increased cellular metabolism, e.g.:

– Increased transferrin production

– Enhance the performance of phagocytes, cells of specific immunity (T cell

production)

– Faster repair mechanisms

Problematic effects of high fever

> 40.7C (105F) can be dangerous (Tachycardia, acidosis, dehydration)

Death at temp. > 44 - 46C

General Microbiology & Immunology (PM 401) theoretical handbook Page 99