see depolarization (change from negative inside neuron to more positive) threshold – if a great enough depolarization occurs, an action potential will occur action potential – very quick – milliseconds Other terms – spike, firing, generating an AP
Na+ K+ Cl- What would each ion do if the ion channel opened based on the concentration gradient?
concentration gradient – ions diffuse from higher concentration to lower concentration electrical gradient - opposite charges attract so ions are attracted to an environment that has a charge that is opposite of the charge they carry!
Na+ K+ Cl- Concentration Gradient Electrical Gradient after the AP (+ intracellular)
INSIDE AXON OUTSIDE AXON (EXTRACELLULAR FLUID) Na+ A- K+ and negative anions are in higher concentration in the intracellular or inside the axon Cl- K+ Cl- K+ Neuron at Rest K+ A- Na+ Cl- K+
Sodium-potassium pump – active force that exchanges 3 Na+ inside for 2 K+ outside
INSIDE AXON OUTSIDE AXON (EXTRACELLULAR FLUID) Na+ A- K+ and negative anions are in higher concentration in the intracellular or inside the axon Cl- K+ Cl- K+ After the action potential K+ A- Na+ Cl- K+ Na+
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