Pyrogens are known to affect which part of the body?

Pyrogens are substances that induce fever by acting on the hypothalamus, which is the part of the brain responsible for regulating body temperature. When pyrogens are detected, they signal the hypothalamus to raise the set point of body temperature, leading to fever as a response to infection or inflammation. This mechanism is a crucial part of the body's immune response, as a higher body temperature can help inhibit the growth of pathogens and enhance immune function.

The hypothalamus's role in thermoregulation makes it the central target for pyrogens, distinguishing it from other organs like the liver, kidneys, or adrenal glands, which have different physiological functions and are not directly involved in the temperature regulation mechanism initiated by pyrogens.