UNIT 4 Flashcards
(37 cards)
membrane potential
difference in electrical charge between inside and outside of cell
sodium-potassium pumps
exchange of 3 Na with 2 K
neurotransmitters
chemicals released by neurons that interact with receptors on membranes of other neurons
postsynaptic depolarization
increases neuron firing
postsynaptic hyperpolarization
decrease neuron firing
graded responses
strength of signal equal to strength of postsynaptic potential
action potentials
electrical impulses which send signals around your body
threshold of excitation
when the sum of depolarizations and hyperpolarizations is enough to depolarize membrane
integration
combining individual signals into overall signal
temporal summation
synapses add up for greater signal
voltage-activated ion channels
ion channels that open or close depending on membrane potential
absolute refractory period
period after initiation of action potential where it is imposible to evoke a second one
relative refractory period
period where you can only fire a neuron again by applying higher-than-normal levels
antidromic conduction
action potential from end of axon to cell body
orthodromic conduction
action potential from cell body to the end of the axon
axodendritic synapses
terminal buttons on dendrites
axosomatic synapses
terminal buttons on somas
axoaxonic synapse
selectively influence one particular synapse
coexistence
neuron with 2 neurotransmitters
ligand
molecule that binds to another
ionotropic receptors
when neurotransmitter binds, immediate postsynaptic potential
autoreceptors
type of metabotropic receptor which monitors number of neurotransmitters in synapse
gap junctions
narrow spaces between adjacent cells bridged by connexins
tripartite synapse
synaptic transmission due to communication between presynaptic and postsynaptic neurons with astrocytes
