structure of neurons
cell membrane
a cell structure that controls which substances can enter or leave the cell.
association neuron
a neuron that carries nerve impulses from one neuron to another
bipolar neurons
a neuron that has only two projections (one axon/one dendrite) from the cell body
multipolar Neuron
a neuron with a single axon and multiple dendrites; the most common type of neuron in the nervous system.
unipolar Neuron
a neuron with one process extending from its cell body
nucleus
a part of the cell containing DNA and RNA and responsible for growth and reproduction
axon
a threadlike extension of a neuron that carries nerve impulses away from the cell body.
central process
branch entering the CNS
neurotransmitter
chemical messengers that cross the synaptic gaps between neurons
efferent
conducting a nerve impulse outward or away from something
afferent
conducting a nerve impulse toward the CNS
path of electrical impulses in the nerve
dendrites - axon- mylein sheath - nodes of ranvier - synapse - neurotransmitters - back to dendrites
nodes of ranvier
gaps in the myelin sheath to which voltage-gated sodium channels are confined.
cell body
largest part of a typical neuron; contains the nucleus and much of the cytoplasm
mylein sheath
layer of fatty tissue that covers many axons and helps speed neural impulses
peripheral process
more distal branch, often associated with a sensory receptor
sensory neuron
neurons that carry incoming information from the sensory receptors to the brain and spinal cord
motor Neurons
neurons that carry outgoing information from the brain and spinal cord to the muscles and glands
interneurons
neurons within the brain and spinal cord that communicate internally and intervene between the sensory inputs and motor outputs
schwann cell
supporting cells of the peripheral nervous system responsible for the formation of myelin.
synaptic endings
swollen terminal knobs on the ends of axon terminal branches
dendrite
the bushy, branching extensions of a neuron that receive messages and conduct impulses toward the cell body
axon terminal
the endpoint of a neuron where neurotransmitters are stored
synapse
the junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron