Neurological and Neurodegenerative DiseasesBy:Jason BlissIf I asked you what the most important organ was then maybe you would say itwas the heart or the lungs, but the vast majority of you would probably have said the brain and for good reason too. The brain controls everything about you. How the Brain WorksThe brain works by transmitting signals through something called neurons, the neurons transmit these signals through what are called axons. And then those axons are covered is a substance called myelin which acts as a sort of insulator that makes signals faster. Now with all of this it may surprise you that the brain is made of mostly fat! In fact it has the most fat out of any organ. But the brain still manages to work like a well oiled machine. After the neurons clump up they form something called grey matter and white matter. And those form to make up the entire brain. The vagus nerve is the main nerve that connect the brain to the rest of the body. It is sometimes called the “Highway of the brain” because of how much information passes through it. The arguably most important part of the brain is called the brainstem, it controls breathing, heartbeat, and other vital systems. Then after that the brain is split into hemispheres. There are also cortexes and lobes, but I won’t go into detail with those. The left hemisphere controls logical thinking. It also controls speech. The right hemisphere controls the creative part of you. It is tied to artistic ability and also helps you recognize people. But both hemispheres control the opposite side of the body, the right controls left and left controls the right side.The Immune SystemWith all these delicate parts that need to be protected the brain has evolved a way to combat any viruses or bacteria that are trying to attack it or any other part of the body. This system is called the immune system. The first cells that come are called phagocytes. The specific phagocyte I will talk about is called a Macrophage. It is the first defense against bacteria and viruses, but they can be infected by viruses, so the body has made cells called natural killer cells to kill any infected cells. While the Macrophages are very powerful in the case of a bacterial infection, the Macrophages will also cause inflammation and call Neutrophiles. The Neutrophils are so powerful that they accidentally harm the body too. Now if this isn’t enough then the macrophages will call a immune cell called the Dendritic cell. The Dendritic cell will start collecting antigens of the virus/bacteria. Then they will travel to a lymphocyte through the lymphatic system. There they will activate T and B cells. The T cells then go to activate the B-cells and and the B-cells produce antibodies that will kill the virus/bacteria. After this there will be leftover T and B cells that will remember the bacteria/virus, and they are called memory T and B cells. This is how vaccines work!