The brain stem runs from the thalamus to the spinal cord, and the top portion of the brain stem is the pons, merely an inch wide but with a huge task. Knowing that our brain has two hemispheres, you may have wondered how the two communicate with each other. Well, the pons takes care of this by connecting the two sides of the cerebellum, and then connecting each side of the cerebellum with the opposite side cerebral hemisphere. The pons also connects the cerebral cortex and the medulla. If you’re thinking the pons is like a bridge, you’d be right, especially as pons means “bridge” in Latin.
At the bottom of the brain stem and the top end of the spinal cord is the medulla, also known as the medulla oblongata. In the time it takes you to say these two words, the medulla oblongata will have regulated your breathing, blood pressure, heart rate, and wakefulness.
And now we arrive at the last bit of the brain responsible for filtering incoming information. Before information is sent to the thalamus it is monitored by the reticular formation, which determines what passes go and what gets turned away. Located in the brain stem, the reticular formation is one swift filter, though that’s not all it handles. It also manages respiration, digestion, sleep patterns, the circulatory system, attention, and arousal.
Feel free to check out some images and an article about the brain in general.
• Side view of the brain (It seems this and the next link are no longer active.)
• Colorful image of the brain stem and cerebellum
• And on KidsHealth you can find a treasure trove of well-written, understandable articles on the body, starting with The Brain Is the Boss.