Brian ate a tuna salad sandwich that had become tainted from…

Brian ate a tuna salad sandwich that had become tainted from being in the sun too long, then became extremely nauseated and felt awful. After that, even the sight of a tuna sandwich caused Brian to feel nauseated. In this scenario, what is the conditioned response (CR)?

As Allison reaches for a box in her garage, out jumps a big…

As Allison reaches for a box in her garage, out jumps a big spider. Her heart begins to race as she withdraws her hand, but soon she realizes that the spider is harmless, and she begins to calm down. Which part of her nervous system is responsible for bringing her back to a normal state of arousal?