A Brief look at the Physiological Basis and Neurological Effect of Brain Tumors :: Biology Essays Research Papers

A Brief look at the Physiological Basis and Neurological Effect of Brain Tumors I've always been interested in medicine, and more specifically, in surgery, but I never really knew which realm of surgery appealed to me the most. So I set out on a quest to find where my future in medicine may lay. I spent time with an orthopedic surgeon and loved the carpentry-like style of the trade, and I spent a week with a general surgeon and watched him fix hernias and cut out moles. But the surgery that struck me the hardest, and the one that I vowed to stay the furthest from, was neurosurgery. The idea of carefully manipulating someone's nervous system in order to give them back the most basic of physical abilities, that of control over one's body, was almost too much to handle. Of all the systems of the body, the nervous system seems to be the most delicate of all. Yet only now, in this class, do I realize the incredible balancing that goes on between so many different components to make the nervous system functional. Furthermore, any alteration to that balance can cause a host of serious problems that could render the nervous system as a whole, or even part of it, completely useless. Tumors are an excellent example of how the balance can be upset, and are one of the most well known of the afflictions to the brain. There are several different kinds of tumors that effect the brain, each is based on what kind or kinds of cells it developed from in the brain. The four main kinds of cells that are effected are astrocytes, oligodendrocytes, ependymal cells, and microglial. Tumors in each of these cell types are referred to as astrocytomas, oligodendrogliomas, microgliomas or primary nervous system lymphoma, and ependymomas. Although tumors can arise from these nervous system cells and others, approximately 65% of brain tumors are astrocytomas. The actual cause of any given tumor is difficult if not impossible to determine, but tumors are generally caused by one of or a combination of three things: radiation, chemicals, and viral agents. Tumors can also be caused during mistakes in DNA replication, but this accounts for a smaller incidence of brain tumors. These genetic alterations can often be harmless, resulting in the effected cell dying and being disposed of by the organism. But on occasion, the effected gene is one that is responsible for having a cell lie dormant , oncogenes, or one that is in place to regulate growth, tumor suppresser genes.