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Questions and Answers
When a neuron is stimulated, ______ channels in the cell membrane open.
When a neuron is stimulated, ______ channels in the cell membrane open.
ion
Neurons have a resting membrane potential of about - 70 ______.
Neurons have a resting membrane potential of about - 70 ______.
mv
The influx of ______ ions causes the membrane potential to become more positive.
The influx of ______ ions causes the membrane potential to become more positive.
Na+
If the depolarization reaches a certain ______, it triggers an action potential.
If the depolarization reaches a certain ______, it triggers an action potential.
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The action potential is an all or nothing response that travels down the ______, leading to release of neurotransmitters at the synapse.
The action potential is an all or nothing response that travels down the ______, leading to release of neurotransmitters at the synapse.
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During an action potential, the membrane potential becomes more positive due to the influx of ______ ions.
During an action potential, the membrane potential becomes more positive due to the influx of ______ ions.
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After the peak of the action potential, ______ channels open, allowing the ions to flow out of the cell.
After the peak of the action potential, ______ channels open, allowing the ions to flow out of the cell.
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The outflow of positive ions helps to restore the ______ membrane potential.
The outflow of positive ions helps to restore the ______ membrane potential.
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During hyperpolarization, the inside of the neuron becomes more ______ compared to the outside.
During hyperpolarization, the inside of the neuron becomes more ______ compared to the outside.
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The combined action of ______ outflow and Na+/K+ pump resorts the original ion concentration gradients.
The combined action of ______ outflow and Na+/K+ pump resorts the original ion concentration gradients.
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Voltage-gated ______ channels open, allowing K+ ions to leave the cell, making the inside more negative.
Voltage-gated ______ channels open, allowing K+ ions to leave the cell, making the inside more negative.
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Sometimes ______ channels open, allowing Cl- ions to enter the cell, contributing to the negative charge inside.
Sometimes ______ channels open, allowing Cl- ions to enter the cell, contributing to the negative charge inside.
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Hyperpolarization makes it less likely for a neuron to fire an action ______.
Hyperpolarization makes it less likely for a neuron to fire an action ______.
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The membrane potential moves further away from the ______ needed to trigger an action potential.
The membrane potential moves further away from the ______ needed to trigger an action potential.
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The resting membrane potential returns to a value of around - ______ mv.
The resting membrane potential returns to a value of around - ______ mv.
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Study Notes
Depolarization Process
- Neurons have a resting membrane potential of approximately -70mV, where the inside of the cell is negatively charged compared to the outside.
- When a neuron is stimulated, ion channels in the cell membrane open, allowing ion movement.
- Sodium (Na+) ions rush into the neuron, causing an influx of positive charge.
- The influx of Na+ ions leads to depolarization, which is the change in membrane potential towards a more positive state.
- If the depolarization reaches a certain threshold, it triggers an action potential.
Action Potential
- The action potential is an all-or-nothing response that travels down the length of the axon.
- The action potential leads to the release of neurotransmitters at the synapse.
Depolarization
- Neurons have a resting membrane potential of around -70mV, with the inside of the cell being negative compared to the outside.
- When a neuron is stimulated, ion channels in the cell membrane open, allowing sodium (Na+) ions to rush in.
- The influx of Na+ ions causes the membrane potential to become more positive, and if it reaches a certain threshold, it triggers an action potential.
- The action potential is an all-or-nothing response that travels down the axon, leading to the release of neurotransmitters at the synapse.
Repolarization
- During an action potential, the membrane potential becomes more positive due to the influx of sodium (Na+) ions.
- After the peak of the action potential, potassium (K+) channels open, allowing K+ ions to flow out of the cell and restore the negative membrane potential.
- The membrane potential returns to its resting state, around -70mV, through the combined action of K+ outflow and the Na+/K+ pump, which restores the original ion concentration gradients.
Hyperpolarization
- During hyperpolarization, the inside of the neuron becomes more negative compared to the outside due to the movement of potassium (K+) ions out of the cell or chloride (Cl-) ions into the cell.
- Voltage-gated potassium channels open, allowing K+ ions to leave the cell, making the inside more negative.
- Sometimes, chloride channels open, allowing Cl- ions to enter the cell, contributing to the negative charge inside.
- Hyperpolarization makes it less likely for a neuron to fire an action potential because the membrane potential moves further away from the threshold needed to trigger an action potential.
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Description
Understand the 5 steps of neuron depolarization, from resting membrane potential to triggering an action potential. Learn how sodium ions and ion channels affect the neuron's membrane potential.
