The human being is considered to be the ultimate form of life on the earth. This is not because the human body is strong and agile. Many other animals posses skills much superior to humans and are able to perform feats humans can only dream of. The one thing that distinguishes humans from all of the other organisms on this planet is the brain. The brain is the site that controls the human body. However, unlike in animals, in man, the brain is also the site of the mind. The mind gives humans superiority over other creatures. It provides humans with the ability to reason, to feel and to adapt. Because of this, man has achieved so much, and has also realized that much more is still ahead.
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 think.
Many sciences were born. Some of them centered around humans. They included, among many others, psychology and neurology. While psychology deals with the mind and human behavior, neurology is the study of the nervous system.
The nervous system of the human being consists of several parts. The main structures are the brain and the spinal chord. The system also includes nerves which sense external and internal stimuli and then relate all information to the central processing unit, i.e. the brain.
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.