The document discusses the main parts of the human brain. It notes that the brain is the largest organ in the human body and is responsible for controlling body functions and coordinating activities. The main parts are the cerebrum, cerebellum, and brain stem. The cerebrum is the largest part and is divided into left and right hemispheres connected by the corpus callosum. The cerebellum coordinates body movement and balance and is located below the cerebrum. The brain stem consists of the midbrain, pons, and medulla oblongata, and is responsible for functions like vision, hearing, blood pressure regulation, and vomiting.