click below
click below
Normal Size Small Size show me how
ahenrique-Nervous
"Nervous" Terms and Definitons
Term | Definition |
---|---|
central nervous system (CNS) | the body's primary information processing system; includes the brain and spinal cord |
peripheral nervous system (PNS) | network of nerves carrying signals into and out of the central nervous system |
nerve | bundle or bundles of neuron fibers surrounded by connective tissue |
stimulus | environmental change that triggers a response |
sensory neuron | nerve cell that carries information from the environment to the central nervous system |
sensory receptor | specialized cell that transmits signals to sensory neurons |
interneuron | nerve cell located entirely in the central nervous system that integrates sensory information and sends motor commands |
motor neuron | nerve cell that carries signals from the central nervous system to muscle or gland cells |
reflex | rapid, automatic response to a stimulus |
dendrite | neuron fiber that receives signals and carries them toward the cell body |
axon | neuron fiber that carries electric impulses away from the cell body and toward other cells |
myelin sheath | thick coat of material that surrounds and insulates the axon of some neurons |
node | uninsulated spaces between the "beads" of a myelin sheath where an action potential can be transmitted |
resting potential | voltage across the plasma membrane of a resting neuron |
depolarization | voltage change that occurs when the difference in charge across a membrane decreases |
threshold | minimum change in a membrane's voltage that must occur to generate an action potential |
action potential | change in voltage across the plasma membrane of a neuron resulting in a nerve signal |
synapse | junction between two neurons or a neuron and another cell where electrical or chemical signals are relayed |
synaptic cleft | tiny space separating a knob of a transmitting neuron from a receiving neuron or other cell |
neurotransmitter | chemical messenger that carries information from one neuron to another or to another cell |