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17.1 Cells and Messengers of the Immune System

1.
The two basic divisions of the immune system are the ________ and the ________.
2 .
The three main types of innate immune cells are ________, ________, and ________.

17.2 What Does Your Immune System Have to Do with Your Behavior?

3.
Isolating, loss of appetite, and feeling fatigue when we are sick are examples of ________.
4 .
Interleukin-1 beta is a pro-inflammatory________, and can induce sickness behaviors.

17.4 What Do Immune System Signals Do Once They Reach the Brain?

5.
Microglia come from this early embryonic structure: ________.
6 .
Microglia help remove synapses that are not being used early in development in a process called ________.
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