AN I MMUNE RESPONSE
The process that produces a fever begins when the immune system encounters a pathogen, such as a bacterium or virus.
1.
The horse is exposed to a disease-causing
organism.
2.
As the immune system responds, white blood
cells release cytokines. 3. Cytokines stimulate inflammatory responses to fight
the infection. 4. One type of cytokine, called a pyrogen, circulates in the blood and is detected by the hypothalamus.
5.
The hypothalamus responds by raising the body’s
“set point” to a higher temperature and releasing neurohormones that cause the
body to heat up.