Module 9 6 Flashcards
What are some specific cytokines that partially induce fever, and what is their source?
Cytokines like IL-1 released from neutrophils and macrophages play a role in inducing fever.
How are these cytokines, which induce fever, referred to in contrast to pathogen-produced pyrogens?
These cytokines are termed endogenous pyrogens to differentiate them from pathogen-produced exogenous pyrogens.
What is the target of pyrogens that influence body temperature?
Pyrogens act directly on the hypothalamus, which is responsible for regulating the body’s temperature.
Why can fever be beneficial in response to infection?
Fever can be beneficial because it can inhibit the growth of certain microorganisms that are highly sensitive to even small increases in body temperature.
What is the potential downside of fever in response to Gram-negative bacterial infections?
Fever may have harmful adverse effects as it can enhance the host’s susceptibility to the effects of endotoxins associated with Gram-negative bacterial infections.
What is the term for the temporary adjustment of the hypothalamic thermostat to a higher level in response to pyrogens?
Fever, or febrile response.
What are exogenous pyrogens, and where are they typically produced?
Exogenous pyrogens are substances produced by pathogens, often associated with endotoxins.
What do exogenous pyrogens stimulate in response to infection?
Exogenous pyrogens stimulate the release of endogenous pyrogens from phagocytic cells.
Name some endogenous pyrogens involved in raising the body’s thermal set point during a fever.
Endogenous pyrogens include tumor necrosis factor-alpha (TNF-α), interleukin-1 (IL-1), interleukin-6 (IL-6), and interferon (IFN).
What is the role of prostaglandin E2 (PGE2) in the fever response?
PGE2 is generated in the hypothalamus in response to endogenous pyrogens and causes the elevation of the body’s thermal set point.
During a fever, how do individuals typically respond to feeling colder?
During a fever, individuals may dress more warmly, decrease body surface area exposure, and may even go to bed to get warm.
What happens to the body temperature when a fever “breaks”?
When a fever breaks, the set point begins to return to normal, resulting in decreased heat production and increased heat reduction mechanisms.
How do individuals typically feel and behave when the fever has broken and the body temperature is returning to normal?
At this stage, individuals may feel very warm, wear cooler clothing, discard covers, and stretch out to cool down.
What does the hypothalamus do once the body has returned to a normal temperature?
The hypothalamus adjusts thermoregulatory mechanisms to support the new temperature.
