Introduction

Abstract

The human brain is the command center for the human nervous system. It contains approximately 86 billion neurons along with other cells that make more than 100 trillion connections. Neurons are the building blocks of the nervous system which includes the brain and spinal cord. Neurons normally do not reproduce or replace themselves, so when they are damaged or die they cannot be replaced by the body. This unique anatomy of brain makes it more complex to understand. Brain is divided into different parts to perform specific functions, i.e., memory formation, movement, emotions, thought, speech, thinking, and many more. The brain is considered as the most complex part of the human body. This three-pound wonderful organ is the center of intelligence, interpreter of the senses, initiator of body movement, and controller of behavior. Contained in its bony shell and bathed by protective fluid, the brain is the originator of all the qualities that define humanity. For centuries, the brain has attracted and fascinated scientists and philosophers, and recently, it has been viewed the brain as nearly incomprehensible. Now, however, the brain is started to relinquish its secrets. Scientists have unfolded many secrets about the brain during 10 years than in past centuries due to the accelerating pace of research in neurological and behavioral science by virtue of new research techniques.