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A nerve impulse results from?
A nerve impulse results from the movement of ions across the cell membrane of a neuron, leading to a change in the electrical charge within the cell. This change in charge creates an action potential that travels down the length of the neuron, allowing for communication with other neurons or cells.
Name the membrane valves that open and close for potassium efflux and sodium influx?
Potassium efflux is controlled by voltage-gated potassium channels, while sodium influx is controlled by voltage-gated sodium channels. These channels open and close in response to changes in membrane potential, regulating the flow of ions in and out of the cell.
What is the reversal of the resting potential owing to an influx of sodium ions called?
The reversal of the resting potential owing to an influx of sodium ions is called depolarization. This occurs when the membrane potential becomes less negative, bringing it closer to the threshold for action potential initiation.
The interior of the cell becomes less negative due to an influx of sodium ions?
The influx of sodium ions causes depolarization of the cell membrane, making the interior less negative. This depolarization can trigger the opening of voltage-gated ion channels, leading to the propagation of an action potential. Sodium-potassium pumps work to restore the original ion concentrations, repolarizing the cell.
The ions that enter the muscle cell during action potential generation are?
Sodium ions (Na+) enter the muscle cell during the depolarization phase of an action potential, causing the cell membrane to become more positively charged. This influx of sodium ions is responsible for the rapid rise in membrane potential.
An action potential is caused by an influx of these ions into the cell?
An action potential is caused by an influx of sodium ions into the cell through voltage-gated sodium channels. This influx of sodium ions results in depolarization of the cell membrane, leading to the generation of an action potential.
Explain why the EPSP is larger if the membrane potential becomes more hyperpolarized than the resting membrane potential?
An excitatory postsynaptic potential (EPSP) is larger when the membrane potential is more hyperpolarized than resting potential because the driving force for sodium ions (Na⁺) influx increases. When the membrane is hyperpolarized, the difference between the resting potential and the sodium equilibrium potential is greater, leading to a stronger current flow when sodium channels open. This enhanced influx of sodium ions results in a more significant depolarization, producing a larger EPSP. Essentially, the larger potential difference allows for a greater excitatory response.
What type of membrane transport causes the depolarization phase of the action potential in neurons?
The depolarization phase of an action potential in neurons is primarily caused by the rapid influx of sodium ions through voltage-gated sodium channels. This influx of sodium ions results in the membrane potential becoming more positive, leading to depolarization of the neuron.
Binding of the neurotransmitters with muscle membrane receptors causes the membrane to become permeable to sodium resulting in the influx of sodium ions an what of the membrane?
depolarization
When hinding of the neurotransmitters with muscle membrane receptors causes the membrane to become permeable to sodium resulting in the influx of sodium ions and what membrane?
action potential of the sarcolemma(the membrane)
Drugs that decrease membrane permeability to sodium are used as what?
Drugs that decrease membrane permeability to sodium are used as local anesthetics. These drugs block the sodium channels and prevent NA+ from entering the cell. NA+ influx is important to dipolarize the membrane.
A nerve impulse results from?
A nerve impulse results from the movement of ions across the cell membrane of a neuron, leading to a change in the electrical charge within the cell. This change in charge creates an action potential that travels down the length of the neuron, allowing for communication with other neurons or cells.
Name the membrane valves that open and close for potassium efflux and sodium influx?
Potassium efflux is controlled by voltage-gated potassium channels, while sodium influx is controlled by voltage-gated sodium channels. These channels open and close in response to changes in membrane potential, regulating the flow of ions in and out of the cell.
A neuron starts to fire an impulse by the influx of what ions?
A neuron fires an impulse by the influx of sodium ions into the cell. This creates a temporary change in the neuron's membrane potential, leading to depolarization and the generation of an action potential.
Opening of sodium channels in the membrane of a neuron results in?
depolarization.
What causes cell membrane to depolarize?
Cell membrane depolarization is caused by the influx of positively charged ions, such as sodium ions, through ion channels in the membrane. This influx of positive charge reduces the voltage difference across the membrane, leading to depolarization.
Is the influx of sodium into the cell during depolarization greater than repolarization?
Yes, the influx of sodium ions (Na+) during depolarization is greater than the outflow of potassium ions (K+) during repolarization. During depolarization, voltage-gated sodium channels open, allowing a rapid influx of Na+, which causes the membrane potential to become more positive. In contrast, during repolarization, voltage-gated potassium channels open more slowly, leading to a slower K+ efflux, resulting in a net increase in positive charge within the cell during depolarization compared to the repolarization phase.
