Transmission of information down an axon is done by the propagation of action potentials Resting potential Recitation 19 Neurobiology Neuron Stage before after action potential Soliudm Potasium Pump Players Na K pump Resting K channel Not a pump Allows K to ow out of the cell Antiporter moves in different directions Moves Na K up concentration gradient Stage threshold and depolarization Players Voltage gated Na channel Opens once threshold is reached Na Flow into the cell Result depolarization Initial ow of Na is down electrical and chemical gradients Na keeps ow in but only do to chemical gradient Forces of chemical gradient equalize Voltage gate Na channel close and inactivate Stage Voltage gated potassium channel repolarization Open when cell is positively charged Allows potassium to rush out making the cell more negative Overshoots slightly re equilbrilate hyperpolarization Stage neurotransmitter release Place Presynaptic cell Players Voltage gated Ca channel Activates when action potential reaches the nerve terminal Ca ows in kinase Synapsin exocytosis of neurotransmitter Stage neurotransmitter reception Ligand gated Na Channel Neutotransmitter binds to channel to open Allows Na to rush in Depolarization new action potential
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