Question

Which of the following statements applies to fever?

a. Viral infection is usually present.
b. Heat-loss mechanisms have been stimulated.
c. It is caused by a signal to the thalamus.
d. It results from release of pyrogens into the circulation.

Answer 1

A fever is caused by the release of pyrogens into the circulation, which reset the body's temperature 'thermostat' and increase body temperature. It is a defense mechanism that helps create a less favorable environment for bacteria.

Step-by-step explanation:

A fever is caused by the release of pyrogens into the circulation. When a bacterium is destroyed by phagocytic leukocytes, these chemicals are released into the blood and circulate to the hypothalamus in the brain. The pyrogens reset the body's temperature 'thermostat,' causing an increase in body temperature. This increase in temperature helps create a less favorable environment for bacteria and activates the body's defense mechanisms.