Neural Communication Flashcards
(48 cards)
How do neurons communicate with each other
Combination of electrical activity (within neuron) and chemical activity (between neurons).
Action potential
Change in voltage that moves along the axon
Potential
Change in voltage
Depolarised
Less negative
What voltage triggers action potential
-65mV
Resting action potential
-70mV
Peak action potential voltage
+45mV
Hyperpolarised
More negative
Stages of action potential
Action potential triggered to -65mV, membrane potential reaches peak value of +45mV, potential depolarises to be less negative than resting potential.
Why does action potential propagate along an axon
Action potential triggers action potentials in adjacent areas.
What happens if depolarisation threshold isn’t met
Voltage propagates along the axon but is subject to ‘decay’
Salatory conduction
Conduction along a myelinated axon
Why does cable conduction occur in salatory conduction
Action potential cannot regenerate due to myelination
Where is action potential regenerated in salatory conduction
Nodes of ranvier
Refractory period
Time period following generation of action potential when no new action potentials can be started, or are harder to start
Absolute refractory period
New action potential cannot be initiated
Relative refractory period
New action potential is more difficult to initiate
Action potential is described as
An all or nothing event
Synapse
Junction between terminal button and a neurones cell membrane
What causes release of neurotransmitter into synaptic cleft
Action potential arriving at terminal buttons
Where does the neurotransmitter bind to on the synapse
Receptor sites on postsynaptic neurone
What happens after the neurotransmitter binds to receptor sites
May increase or sometimes reduce the likelihood of the cell depolarising
Where does axodendritic synapses occur
The surface of a dendrite or dendritic spine
Where do axosomatic synapses occur
On a cell membrane
