During the course of evolution, ever since early Homo sapiens and his ancestors walked on the surface of the earth, man has wondered about himself, and how he relates to the natural world. People learned and adapted to new lifestyles. As time passed, humans learned to record history. They analyzed past events and applied this knowledge to solve problems. These processes improved as more and more people supplied their experiences to the common pool of knowledge. Such co-operation created the modern man with his superb ability to thin

Recently, some theories were presented as to the origin of the disease. Various scientific teams continually come up with possible clues. Doctors at San Francisco Athena Neurosciences institute recently made several connections between protein-splitting enzymes (Thrombin) and the destruction of nerve cells in the cerebral cortex. These cells are vital in the production of Acetylcholine, a neurotransmitter which permits smooth conduction of impulses. Their observations lead to a hypothesis which stated that if Thrombin is released from the blood stream into the fragile cavities between brain cells, it can start destroying them. However it will only do that if enzyme inhibitors are absent. These inhibitors are present in normal human beings, and scientists are currently searching for definite evidence that persons without these inhibitors are susceptible to Alzheimer's disease.

There are also other theories about this disorder. In the late 1980's a connection was made between Alzheimer's and Down syndrome. Both diseases seem to have their appropriate genes on the twenty-first chromosome. The research began because it was observed that many Down syndrome patients develop Alzheimer's at an early age. A third theory states that the disease is caused by the harmful effects of aluminum accumulation in brain tissue. However, research in this and other areas still continues but no effective cure has been found. Alzheimer's can be treated and slowed down by various pharmaceuticals, but it cannot be reversed.

Because of man's rapid evolution in technology and medicine, humans now know a great deal more about their own nervous system then they did even a few years ago. This increase in knowledge is partly due to the recent advances in nuclear medicine. Although X-ray machines have been the chief mechanical tools for internal observations of the human body since Wilhelm Roentgen discovered X-rays in 1901, the development of computers made it possible for better and more accurate techniques to be applied to scan the human body. These methods employ various scanners like the CAT, PET, MRI and SPECT.

The CAT is an acronym for Computerized Axial Tomography. This method of scanning generally involves X-rays and enables scientists to view the inside of the head in a three dimensional format on a computer screen. PET stands for Positron Emission Tomography and it is much more complicated than the CAT scan. PET machines bombard the subject with doses of positrons-the anti-matter equivalents of the electrons. As the positrons enter the body, they encounter electrons which are escaping from radioactive elements which have been

Some common words found in the essay are:
Multiple Sclerosis, Human Brain, Trimethadione Carbamazepine, Carbon Phosphorus, Athena Neurosciences, Scanning Microscopes, Emission Tomography, Axial Tomography, Wilhelm Roentgen, Computed Tomography, nervous system, human body, spinal chord, multiple sclerosis, brain spinal, alzheimer's disease, nerve cells, brain spinal chord, research continues, spinal column, cure disease,
Approximate Word count = 1772
Approximate Pages = 7 (250 words per page double spaced)