Describe the organization of the nervous system in regard to structure and function.

neurons (nervous system cells) and nerves (bundles of neurons)

nervous system uses for communication

central nervous system (CNS) and Peripheral nervous system (PNS)

Two main divisions of nervous system

central nervous system (CNS)

composed of the brain and spinal cord and serves as the central processing center

peripheral nervous system (PNS)

network of all the nerves in the body that sends messages to and from the central processing center.

Sensory neurons

This carry afferent (incoming) messages to the brain or spinal cord

Motor neurons

carry efferent (outgoing) messages away from the brain and spinal cord.

the somatomotor

efferent messages travel on motor neurons to stimulate skeletal muscles to move the body

autonomic division

messages go to glands, the cardiac muscle of the heart, or the smooth muscle of hollow organs and blood vessels

parasympathetic and sympathetic

two subdivisions of autonomic division

parasympathetic division

This sends electrical messages to carry out functions for vegetative activities such as digestion, defecation, and urination.

sympathetic division

sends electrical messages to prepare the body for physical activity, often referred to as fight or flight