Frontal lobe : Plays a role in mood regulation, pain transmission, sleep, and arousal Thalamus : Middle portion of the brainstem Hypothalamus Amygdala : Layer of gray matter covering the cerebrum Medulla oblongata : Connects the brainstem to the spinal cord Pons : Superior portion of the brainstem Midbrain : Middle meningeal layer Cerebral cortex : Main gateway into the cerebral cortex Arachnoid mater : Most anterior lobe of the brain : Plays a role in behavior and emotion : Regulates the autonomic nervous system.