sensory impulse![click to hear](/images/speaker.jpg)
Electrical signal propagated along the nerve fibers (axons) enabling the nerve cells to communicate and to transmit messages within the organism.
motor end plate ![click to hear](/images/speaker.jpg)
Contact zone between the axonal end of the motor neuron and the muscle fiber that causes muscle movement.
white matter ![click to hear](/images/speaker.jpg)
Section of the spinal cord made up of nerve fibers (axons) and surrounding the gray matter.
gray matter ![click to hear](/images/speaker.jpg)
Central part of the spinal cord primarily made of the cell bodies of neurons.
muscle fiber ![click to hear](/images/speaker.jpg)
Component tissue of the muscle; it contracts in response to a nerve impulse from the central nervous system.
sensory neuron ![click to hear](/images/speaker.jpg)
Neuron transmitting information gathered by sensory receptors to the central nervous system.
sense receptor ![click to hear](/images/speaker.jpg)
Peripheral terminal of the sensory neuron receiving a stimulus (touch, noise or other) and transmitting it to the spinal cord in the form of nerve impulses.
skin ![click to hear](/images/speaker.jpg)
The body’s outer protective casing whose internal layer (dermis) is rich in veins and nerves.
spinal cord ![click to hear](/images/speaker.jpg)
Part of the central nervous system located in the spinal column; it receives and transmits nerve information and initiates reflex actions.
synapse ![click to hear](/images/speaker.jpg)
Contact zone between two neurons through which nerve impulses are transmitted.
motor root ![click to hear](/images/speaker.jpg)
Bundle of motor nerve fibers (axons) communicating information from the spinal cord to the periphery of the body, especially the muscles.
motor neuron ![click to hear](/images/speaker.jpg)
Neuron conducting nerve impulses from the central nervous system to the peripheral organs, such as the muscles.
spinal nerve ![click to hear](/images/speaker.jpg)
Nerve formed by the union of the sensory and motor roots; it communicates nerve messages between the spinal cord and the various parts of the organism.
protoneuron ![click to hear](/images/speaker.jpg)
First neuron of the sensory tract; it transmits information from a sensory organ to the spinal cord.
spinal ganglion ![click to hear](/images/speaker.jpg)
Bulge of the posterior sensory root of the spinal nerve; it encloses the cell bodies of the neuron sensors.
sensory root ![click to hear](/images/speaker.jpg)
Bundle of sensory nerve fibers (axons) communicating information from the periphery of the body to the spinal cord.