The brain and their functions: Frontal Lobe, Parietal Lobe, Occipital Lobe, Cerebellum and Temporal Lobe. It also discusses the right and left hemispheres of the brain and what they are responsible for controlling.
Check out this Cartoon on how your thyroid works. Thyroid issues can get complicated, so this might help explain a little bit better what dotors do not explain to their patients. Check out that T-shirt here: