Structure and function of the brain
The brain lies in the cranium and has about 86 billion neurons. It consists of the brain stem, diencephalon, cerebellum and cerebral hemispheres. The brain stem includes the medulla, pons and midbrain; most of the 12 pairs of cranial nerves leave it, among them the vagus nerve, which controls the heart, lungs and stomach. The medulla contains centres for breathing, heartbeat, digestion and protective reflexes (sneezing, coughing, swallowing). The pons links the medulla with other parts. The midbrain controls muscle tone and visual and auditory orienting reflexes. The diencephalon coordinates metabolism, body temperature, hunger and thirst and routes sensory impulses to the hemispheres. The cerebellum controls accuracy of movement and body balance; if damaged, movements become uncoordinated. Protecting the head from blows – wearing a helmet on a bicycle or scooter – protects the brain.
Brain-parts poster: write one function by each part (e.g. “cerebellum – balance”). Quiz each other. Try “standing on one leg” for balance in a safe place near an adult.