The Nervous System

ORGANIZATION OF NERVOUS SYSTEM
Structural classification-The Nervous System is the master controlling and communicating system in the body. The nervous system has subdivisions- the central nervous system and the peripheral nervous system. The central nervous system includes the brain and the spinal cord, which interprets incoming sensory information and then acts as the integrating and command centers of the nervous system. The peripheral system includes all of the nerves outside the central nervous system. Spinal nerves carry impulses to and from the spinal cord and cranial nerves carry impulses to and from the brain. Theses nerves serve as links in the communication network, connecting everything together.
Functional Classification- The functional classification deals only with the peripheral nervous system. The sensory (afferent) division consist of nerve fibers that convey impulses to the central nervous system from sensory receptors in various parts of the body. Somatic sensory fibers deliver impulses from the skin, skeletal muscles and joints. Visceral sensory fivers transmit impulses from visceral organs. The sensory division keeps the central nervous system informed about the things going around the body. The motor (efferent) division carries impulses from the central nervous system to the specific organs. The impulses activate muscles and glands. The motor division is broken into a subdivision-somatic and autonomic nervous system. The somatic nervous system allows us to voluntary control our skeletal muscles. The autonomic nervous system controls events that are involuntary like activity of smooth and cardiac muscles and glands.
NEURON STRUCTURE
Neurons are nerve cells that transmit messages. The cell body of the neuron is the metabolic center of the cell and contains the nucleus. Processes extend from the cell body. In the