Lots. The smallest count of brain parts is often 1 left hemisphere, 1 right hemisphere. 2. These are composed of 4 lobes each. 8. Here it gets fuzzy. Each lobe, and the underlying hindbrain and mindbrain too, can be cut up in many different ways. It is like asking how many parts a cow has. Legs, body, head - 6. A leg is one part, or it is bone and muscle and skin, so 3. But each muscle has different cuts for a butcher, or different strands for an anatomist. Both are valid divisions, so the answer depends who you ask, or how you make your classifications. Each of the hundreds of brain nuclei are also made of billions of cells, each with thousands of different but specific connections. Lots.