| Figure 16a: | Forebrain | Hindbrain | Midbrain |
| Figure 16b: | Cerebellum | Medulla | Pons | Reticular Formation | Thalamus |
Part 1: Image-Mapped Tutorial
Part 2: Matching Self-Test:
16a |
16b
Part 3: Multiple-Choice Self-Test
Both the medulla and pons contain the Reticular Formation and the raphe' system. These nuclei synthesize norepinephrine and serotonin and contain high levels of these neurotransmitters, respectively. The neurotransmitters synthesized within each of these brainstem nuclei, increase physiological and behavioral arousal in the distant cortical regions to which they project. Norepinephrine of the reticular formation increases arousal to external events, whereas serotonin of the raphe' system increases arousal to internal events. Additional information on the role of the reticular nucleus and raphe system in arousal and sleep is provided elsewhere.