Pyrogens

Definition

Pyrogens are substances that cause an increase in body temperature by triggering the hypothalamus to elevate the body's set point. They can be exogenous, originating from outside the body such as bacteria, or endogenous, produced within the body like cytokines.

5 Must Know Facts For Your Next Test

1. Exogenous pyrogens are often bacterial toxins like lipopolysaccharides (LPS) found in gram-negative bacteria.
2. Endogenous pyrogens include cytokines such as interleukin-1 (IL-1), tumor necrosis factor-alpha (TNF-alpha), and interleukin-6 (IL-6).
3. Pyrogens interact with the hypothalamus in the brain to raise the body's thermal set point, leading to fever.
4. The presence of pyrogens is a common trigger for inflammation and an integral part of innate nonspecific host defenses.
5. Detection of pyrogens is critical in medical settings to ensure that intravenous solutions and medical devices are sterile and safe.

Review Questions

Related terms

Inflammation:

A biological response to harmful stimuli marked by redness, heat, swelling, and pain.

Cytokines:

Small proteins released by cells that have a specific effect on interactions and communications between cells.

Hypothalamus:

A region of the brain responsible for regulating body temperature among other functions.