Question | Answer |
Polarized | The inside is negatively charged with respect to the outside |
Repolarization | K+ channels open and K+ ions rush out of the cell, cell returns to resting potential (becomes more negative) |
Depolarization | Na+ channels open and Na+ ions rush into the cell, cell becomes less negative/ more positive |
Divergence | A single neuron sends impulses to many other neurons, amplifies an impulse |
Synapse | The junction between two communicating neurons |
Summation | Several sub-threshold impulses are combined to reach the threshold |
Facilitation | Sub-threshold stimulus causes the neuron to be more easily excited |
Convergence | a single neuron receives impulses from two or more axons, causes strong stimulation or inhibition |
Saltatory conduction | Nerve impulses 'jump' from node of Ranvier to node of Ranvier |
Inhibitory Neurotransmitter | Blocks an action potential in the post-synaptic neuron |
Excitatory Neurotransmitter | Increases post-synaptic membrane |
All-or-none response | If a neuron responds at all, it responds completely. Greater intensity of stimulation triggers more impulses per second, not stronger impulses |
Resting potential | A resting nerve is not being stimulated, has more potassium (K)+ ions inside, and more sodium (Na)+ ions outside. Inside has a more negative charge, outside has a more positive charge. |
Action potential | Na+ channels open, Na+ ions rush into cell. Interior becomes more positive. Na+ channels close. K+ channels open, K+ ions rush out of cell. Cell returns to resting potential/ more negative. |
Pre-synaptic neuron | The sending neuron (axon) |
Post-synaptic neuron | The receiving neuron (dendrites) |
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