Host Response to Infection ✅ Flashcards
What is the first line of defence against pathogens?
The innate immune system
What is the problem with the innate immune system?
It is a rapid and broad response that causes collateral damage to host tissues
What limits the damage caused to the host tissues caused by the innate immune system?
When the pathogen is eliminated the host response shifts from pro- to anti-inflammatory and homeostasis is restored
What can sometimes happen to the inflammatory reaction caused by infection?
The inflammatory response becomes so potent or widespread that it causes systemic physiological derangements in the host
What is produced when a potent or widespread inflammatory response causes systemic physiological derangement?
Sepsis
What is fever defined as?
Core temperature greater than 38
What causes a fever?
Up-regulation of the set-point for body temperature homeostasis
What molecules are involved in the generation of fever?
Pyrogenic mediators
What is the most important pyrogenic mediator?
Prostaglandin E2 (PGE2)
Where do pyrogenic mediators act?
Nuclei in the pre-optic area of the brain
What is triggered when pyrogenic mediators act on nuclei in the pre-optic area of the brain?
Neuronal mechanisms to increase heat generation and reduce heat loss
What neuronal mechanisms increase heat generation/reduce heat loss?
- Brown fat thermogenesis
- Shivering
- Skin vasoconstriction
How is fever beneficial in infection?
Inhibits pathogen replication
How can fever be harmful?
Increases metabolic demand when essential tissues are suffering critical levels of hypoxia and ischaemia
What might be involved in the management of fever?
- Antipyretics
- Regular fluids
