Neurons

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