The brain is the most complex part of the human body. This three-pound organ is the seat of intelligence, interpreter of the senses, initiator of body movement, and controller of behavior. Lying in its bony shell and washed by protective fluid, the brain is the source of all the qualities that define our humanity. The brain is the crown jewel of the human body.
For centuries, scientists and philosophers have been fascinated by the brain, but until recently they viewed the brain as nearly incomprehensible. Now, however, the brain is beginning to relinquish its secrets. Scientists have learned more about the brain in the last 10 years than in all previous centuries because of the accelerating pace of research in neurological and behavioral science and the development of new research techniques. As a result, Congress named the 1990s the Decade of the Brain. At the forefront of research on the brain and other elements of the nervous system is the National Institute of Neurological Disorders and Stroke (NINDS), which conducts and supports scientific studies in the United States and around the world.
The brain serves many important functions. It gives meaning to things that happen in the world surrounding us.
We have five senses: sight, smell, hearing, touch and taste. Through these senses, our brain receives messages, often many at one time. It puts together the messages in a way that has meaning for us, and can store that information in our memory. For example: An oven burner has been left on. By accident we touch the burner. Our brain receives a message from skin sensors on our hand. Instead of leaving our hand on the burner, our brain gives meaning to the signal and tells us to quickly remove our hand from the burner. Heat has been felt. If we were to leave our hand on the burner, pain and injury would result. As adults, we may have had a childhood memory of touching something hot that resulted in pain or watching someone else who has done so. Our brain uses that memory in a time of need and guides our actions and reactions in a harmful situation.
With the use of our senses: sight, smell, touch, taste, and hearing, the brain receives many messages at one time. It can select those which are most important. Our brain controls our thoughts, memory and speech, the movements of our arms and legs and the function of many organs within our body. It also determines how we respond to stressful situations (i.e. writing of an exam, loss of a job, birth of a child, illness, etc.) by regulating our heart and breathing rate. The brain is an organized structure, divided into many parts that serve specific and important functions.