anatomy nervous system

central nervous system

part of the nervous system made up of the brain and spinal cord.

peripheral nervous system

part of the nervous system made up of the nerves outside the CNS.

sensory (afferent) division

division of the PNS composed of nerves that carry information TO the CNS.

motor (efferent) division

division of the PNS composed of nerves that carry information FROM the CNS.

somatic division

part of the motor division responsible for conscious or voluntary control of skeletal muscle and reflexes.

autonomic division

part of the motor division responsible for automatic or involuntary responses.

neuroglia

cells of the nervous system that insulate, support, and protect delicate neurons.

neurons

nerve cells

dendrites

fibers that receive and convey message to the cell body of a neuron.

cell body

the metabolic center of a neuron; contains the nucleus.

axon

neuron fibers that conduct impulses away from the cell body.

axon terminal

branches at the end of an axon that contain vesicles of neurotransmitters and responds to a nerve impulse.

myelin

white, fatty material found in neuron coverings.

myelin sheath

covering composed of schwann cells that insulates nerve fibers and increases the rate of transmission.

schwann cell

cells that are wrapped around axons; produce myelin.

node of ranvier

gaps along the axon that are not covered by myelin sheath; impulses jump from node to node.