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