How can we help?

You can also find more resources in our Help Center.

20 terms

Ch 3 Neurophysiology

quiz 4 notecards
STUDY
PLAY
ion channel
specialized protein molecule that permits specific ions to enter or leave the cell
action potential
brief electrical impulse that provides the basis for conduction of information along an axon
threshold of excitation
the value of the membrane potential that must be reached to produce an action potential
voltage dependent ion channel
an ion channel that opens or closes according to the value of the membrane potential
all or none law
principle that once an action potential is triggered, it transmits with full force to the end of the fiberout
cable properties
passive conduction of electrical current, in a decremental fashion, down the length of an axon
saltatory conduction
conduction of action potentials by myelinated axons, appears to jump from one node of ranvier to another
presynaptic membrane
membrane of terminal button lies next to postsynaptic membrane, through which NT is released
postsynaptic membrane
membrane located on the dendrite of a neuron receives info, concept of chemical transmission
postsynaptic potentials
alterations in the membrane potential of a postsynaptic neuron, produced by the liberation o fa neurotransmitter at the synapse
post synaptic receptor
receptor molecule in the postsynaptic membrane of a synapse that contains a binding site for a neurotransmitter
ionotropic receptor
receptor that contains a binding site for a neurotransmitter and an ion channel that opens when a molecules of the neurotransmitter attaches to the binding site
metabotropic receptor
receptor that contains a binding site for a neurotransmitter, activates an enzyme begins a series of events , opening an ion channel elsewhere in the membrane of the cell when a molecules of the neurotransmitter attaches to the binding site
g protein
a protein coupled to a metabotropic receptor; conveys messages to other molecules when a ligand binds with and activates the receptor
second messenger
chemical produced when a g protein activates an enzyme; carries a signal that results in the opening of the ion channel or causes other events to occur in the cell
neural integration
process inhibitory/excitatory postsynap. potentials control the rate of firing of a neuron
excitatory postsynaptic potential
EPSP excitatory depolarization of the postsynap. membrane of a synapse caused by the liberation of a NT by the terminal button
inhibitory postsynaptic potential
IPSP inhibitory hyperpolarization of the postsynap.
reuptake
the reentry of a NT just freed by a terminal button back through its membrane, terminates the potential
enzymatic deactivation
destruction of a NT by an enzyme after its release, breakdown and reformed at a later time (recycling)