Question

The ________ is a structure in the brain stem that plays a role in sleep, dreaming, left-right body coordination, and arousal.

Answer 1

The answer is "Pons"!

Answer 2

Using what I remember from my biology class, this is my answer:

The Reticular Activating System is a part of the brain connected to the brain stem that controls those specific aspects of the brain and is connected via the thalamus to the cortex.