Neurology is the major branch in medical science that deals with the disorder and illnesses in the nervous system. The term neurology originates from a blend of two words - "neuron" which means nerve and "logia" signifying "the study of". The brain consists of nearly 100 billion neurons, which can generate the impulses on their own and can receive, transmit impulses from adjoining cells. Neurology consists the study of: The peripheral nervous system, the autonomic nervous system and central nervous system. The functional and structural disorders which ranges from birth defects through to degenerative diseases likely Parkinsons disease and Alzheimers disease.