action potential
the electric pulse that runs through a neuron (cannot be passed between neurons)
afferent neuron
part of the peripheral nervous system; sends sensory input to the brain from other parts of the body
efferent neurons
part of the peripheral nervous system; sends motor commands from the brain to other parts of the body
interneurons
neurons that are part of the central nervous system
glial cells
cells that give structure to the brain (holds it together)
somma
the body of a neuron; where the nucleus and other central organelles are located
dendrites
large branches surrounding the somma that receive chemical messages from other neurons and start the action potential
axon
the large stem that stretches from the somma to another neuron (can vary widely in length); where the action potential travels
myelin sheath
segmented fatty insulation surrounding the axon
axon terminal
where neurotransmitters are stored until they are used to send messages to the next neuron
multiple sclerosis
medical condition caused by deterioration of the myelin sheath
synapse
the space between neurons, where messages are sent