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Questions and Answers
What is the state of voltage-gated sodium channels at rest?
What is the state of voltage-gated sodium channels at rest?
What contributes to the repolarization phase of the action potential?
What contributes to the repolarization phase of the action potential?
What triggers the opening of more voltage-gated sodium channels during the action potential?
What triggers the opening of more voltage-gated sodium channels during the action potential?
What causes the sharp rise in membrane potential during the depolarization phase?
What causes the sharp rise in membrane potential during the depolarization phase?
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What is the state of voltage-gated sodium channels during the resting state of a neuron?
What is the state of voltage-gated sodium channels during the resting state of a neuron?
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What contributes to the repolarization phase of the action potential?
What contributes to the repolarization phase of the action potential?
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What triggers the opening of more voltage-gated sodium channels during the action potential?
What triggers the opening of more voltage-gated sodium channels during the action potential?
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What causes the sharp rise in membrane potential during the depolarization phase?
What causes the sharp rise in membrane potential during the depolarization phase?
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What contributes to the repolarization phase of the action potential?
What contributes to the repolarization phase of the action potential?
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What triggers the opening of more voltage-gated sodium channels during the action potential?
What triggers the opening of more voltage-gated sodium channels during the action potential?
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What causes the sharp rise in membrane potential during the depolarization phase?
What causes the sharp rise in membrane potential during the depolarization phase?
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What is the state of voltage-gated sodium channels at rest?
What is the state of voltage-gated sodium channels at rest?
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What is the state of voltage-gated sodium channels during the resting state of a neuron?
What is the state of voltage-gated sodium channels during the resting state of a neuron?
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What triggers the opening of more voltage-gated sodium channels during the action potential?
What triggers the opening of more voltage-gated sodium channels during the action potential?
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What contributes to the repolarization phase of the action potential?
What contributes to the repolarization phase of the action potential?
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What causes the sharp rise in membrane potential during the depolarization phase?
What causes the sharp rise in membrane potential during the depolarization phase?
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What is the role of voltage-gated potassium channels during the repolarization phase?
What is the role of voltage-gated potassium channels during the repolarization phase?
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What happens to voltage-gated sodium channels after reaching their peak during the action potential?
What happens to voltage-gated sodium channels after reaching their peak during the action potential?
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What is the effect of depolarization reaching a certain threshold during the action potential?
What is the effect of depolarization reaching a certain threshold during the action potential?
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What is responsible for maintaining the resting membrane potential in a neuron?
What is responsible for maintaining the resting membrane potential in a neuron?
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What is the primary function of voltage-gated sodium channels during depolarization?
What is the primary function of voltage-gated sodium channels during depolarization?
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What leads to a decrease in membrane potential during repolarization?
What leads to a decrease in membrane potential during repolarization?
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What triggers the opening of voltage-gated sodium channels during the depolarization phase of the action potential?
What triggers the opening of voltage-gated sodium channels during the depolarization phase of the action potential?
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What contributes to the repolarization phase of the action potential?
What contributes to the repolarization phase of the action potential?
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What is the state of voltage-gated sodium channels at rest?
What is the state of voltage-gated sodium channels at rest?
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What is responsible for maintaining the resting membrane potential in a neuron?
What is responsible for maintaining the resting membrane potential in a neuron?
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Which type of muscle is responsible for involuntary, rhythmic contractions in the body?
Which type of muscle is responsible for involuntary, rhythmic contractions in the body?
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Which type of muscle is primarily under the control of the autonomic nervous system?
Which type of muscle is primarily under the control of the autonomic nervous system?
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Which type of muscle is attached to bones by tendons and is responsible for voluntary movement?
Which type of muscle is attached to bones by tendons and is responsible for voluntary movement?
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Which type of muscle contracts rhythmically to pump blood throughout the body?
Which type of muscle contracts rhythmically to pump blood throughout the body?
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Study Notes
Voltage-Gated Sodium Channels
- At rest, voltage-gated sodium channels are closed, preventing sodium ions from entering the neuron.
- During the resting state, channels are not active and contributing to a stable membrane potential.
Action Potential Phases
- Repolarization phase occurs due to the opening of voltage-gated potassium channels, allowing potassium to exit and restore the negative internal charge.
- When depolarization reaches a certain threshold, it triggers the opening of additional voltage-gated sodium channels, amplifying the action potential.
- Sharp rise in membrane potential during depolarization results from the rapid influx of sodium ions through opened voltage-gated sodium channels.
Role of Voltage-Gated Sodium Channels
- Primary function during depolarization is to facilitate a rapid influx of sodium ions, significantly raising the membrane potential.
- After reaching peak potential, voltage-gated sodium channels become inactivated, stopping sodium ion entry.
Resting Membrane Potential
- The resting membrane potential is primarily maintained by the activity of the sodium-potassium pump, which expels sodium ions and retains potassium ions.
Types of Muscle
- Cardiac muscle is responsible for involuntary, rhythmic contractions that pump blood throughout the body.
- Smooth muscle, controlled by the autonomic nervous system, is found in various organs and also facilitates involuntary movements.
- Skeletal muscle is attached to bones by tendons and responsible for voluntary movements.
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Description
Test your knowledge on the changes in ionic channels during the resting and depolarization phases of a neuron's action potential. Understand the dynamics of voltage-gated sodium and potassium channels in maintaining and altering the membrane potential.
