This cornell is about science. My question is "What are the systems of a brain?" The purpose of the systems of the brain is very important because if one part of the barin doesnt work the whole brain would not work. All the parts of a brain has to work so the brain could be able work right. I learned that the brain has different parts and has different systems that controls a brain. Like for example, the brain has nervous system, impulses, spinal cord, motor neurons, PNS, CNS etc. I improved my reading the chapters of the brain twice. Well when our science professor hand out the exam of the brain I was totally scared that I was going to failed the exam but when we corrected the quiz I got one wrong out of 10. My advice is that you should study before being told that you have exam for a subject you already learned.