A propagated change in the transmembrane potential of excitable cells, initiated by a change in the membrane permeability to sodium ions
Action potential
The period between the initiation of an action potential and the restoration of the normal resting potential; during this period, the membrane will not respond normally to stimulation
Refractory period
Neurotoxin responsible for the neurilemm a that surrounds axons in the peripheral nervous system
Schwann cells
Phagocytes neuroglia in the central nervous system
Microglia
Central nervous system neuroglia that maintain cellular organization within gray matter and provide a myelin sheath in areas of white matter
Oligodendrocytes
One of the four types of neuroglia in the central nervous system; responsible for maintaining the blood-brain barrier by the simulation of endothelial cells
Astrocytes
Cells of the central nervous system and peripheral nervous system that support and protect neurons.
Neuroglia
Form the the efferent division of the PNS, stimulate or modify the activity of a peripheral tissue,organ, or organ system.
Motor neurons
Are always located in the CNS and may be situated between sensory and motor neurons. They distribute sensory inputs and coordinate motor outputs
Inter neurons
A chemical compound released by one neuron to affect the transmembrane potential of another
Neurotransmitter
The site of communication between a nerve cell and another cell
Synapse
The efferent division of the nervous system that innervates skeletal muscles
SNS
Centers, nuclei, tracts, ganglia, and nerves involved in the unconscious regulation of visceral functions; includes components of the central nervous syste, and the peripheral nervous system
ANS
A peripheral gland or muscle cell innervated by a motor neuron
Effector
Sensory structures that either detect changes in the internal environment or respond to the presence of specific stimuli
Receptor
The elongate extension of a neuron that conducts an action potential
Axon
All neural tissue outside the CNS
PNS
The brain and spinal cord
CNS
A compound found in tobacco that binds to specific ACH receptor sites and stimulates the synaptic membrane
Nicotine
A fatal disease caused by a virus that reaches the CNS via retrograde flow along peripheral axons
Rabies
A compound that disrupts normal nervous system function by interfering with the generation or propagation of action potentials
Neurotoxin
A genetic abnormality involving the metabolism of gangoliosides, important components of neuron plasma membranes.
Tach-Sachs disease
Neuropeptides produced in the brain and spinal cord that appear to relieve pain and affect mood
Endorphins