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Why are most action potentials generated in response to a long stimulus that is above threshold?
Action potentials are generated in response to a long stimulus above threshold because it allows for the full development of the depolarization phase. This prolonged depolarization leads to the activation of voltage-gated sodium channels, triggering the rapid influx of sodium ions and initiating the action potential. A sustained stimulus ensures that the membrane potential remains above threshold for a sufficient time to generate an action potential.
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Strong stimuli cause the amplitude of action potentials generated to increase?
Yes. ....Up to a point. There is a threshold the stimulus must surpass before creating a CAP (compound action potential). Anything below this threshold is called subthreshold. Once the stimulus is strong enough cause a CAP it is a stimulus threshold. At this point the CAP will continue to increase as the intensity of the stimulus increases (now termed suprathreshold) until a maximal stimulus causes a maximum response. Any stimulus stronger than the maximal stimulus is called a supramaximal and does not result in any larger a CAP than the maximum response caused by the maximal stimulus. source: http://www.unmc.edu/physiology/Mann/mann12.html
What stimulus below this intensity will result in no response in a neuron?
Any stimulus below the neuron's threshold potential will not result in a response, as it is not strong enough to generate an action potential. Neurons require a minimum level of stimulus intensity to reach the threshold potential and fire an action potential.
What is the response if you increase the stimulus intensity past the threshold level for a neuron?
Increasing the stimulus intensity past the threshold level for a neuron will not further increase the action potential generated. Once the threshold is reached, the neuron will fire an action potential at its maximum intensity.
A muscle fiber will not respond to a stimulus until that stimulus reaches what?
A muscle fiber will not respond to a stimulus until that stimulus reaches the threshold level needed to trigger an action potential. This threshold level is the minimum amount of stimulus required to elicit a response from the muscle fiber.
Is conducting stimulus strong enough to generate a nerve impulse?
Yes, a stimulus needs to reach a certain threshold level of strength in order to generate a nerve impulse. This threshold is required to depolarize the cell membrane and initiate the action potential. If the stimulus is not strong enough to reach this threshold, no nerve impulse will be generated.
Strong stimuli cause the amplitude of action potentials generated to increase?
Yes. ....Up to a point. There is a threshold the stimulus must surpass before creating a CAP (compound action potential). Anything below this threshold is called subthreshold. Once the stimulus is strong enough cause a CAP it is a stimulus threshold. At this point the CAP will continue to increase as the intensity of the stimulus increases (now termed suprathreshold) until a maximal stimulus causes a maximum response. Any stimulus stronger than the maximal stimulus is called a supramaximal and does not result in any larger a CAP than the maximum response caused by the maximal stimulus. source: http://www.unmc.edu/physiology/Mann/mann12.html
The all or none principle states that?
The all-or-none principle in physiology states that once a nerve impulse reaches a certain threshold, a neuron will fire at its maximum potential. If the stimulus is strong enough to trigger an action potential, the response will occur at full strength. If the stimulus is below the threshold, no response will be triggered.
What stimulus below this intensity will result in no response in a neuron?
Any stimulus below the neuron's threshold potential will not result in a response, as it is not strong enough to generate an action potential. Neurons require a minimum level of stimulus intensity to reach the threshold potential and fire an action potential.
What are the key differences between action potential and graded potential in terms of their mechanisms and functions?
Action potentials are rapid, all-or-nothing electrical signals that travel along the axon of a neuron, triggered by a threshold stimulus. Graded potentials are slower, variable electrical signals that occur in response to a stimulus, but do not necessarily reach the threshold for an action potential. Action potentials are essential for long-distance communication in the nervous system, while graded potentials play a role in short-distance signaling and can summate to trigger an action potential.
Why is the amplitude of the compound action potential recorded from the frog sciatic nerve increased when the voltage of the stimulus was increased above the threshold value?
Increasing the stimulus voltage above the threshold value results in recruiting more nerve fibers to generate action potentials. This leads to a greater number of action potentials being generated simultaneously along the nerve, resulting in a larger compound action potential amplitude being recorded.
What is the response if you increase the stimulus intensity past the threshold level for a neuron?
Increasing the stimulus intensity past the threshold level for a neuron will not further increase the action potential generated. Once the threshold is reached, the neuron will fire an action potential at its maximum intensity.
When a neuron receives a stimulus that is very strong?
When a neuron receives a very strong stimulus, it may reach its threshold potential and fire an action potential. This can lead to the release of neurotransmitters, sending a signal to other neurons. The strength of the stimulus can affect the frequency of action potentials generated by the neuron.
The minimum stimulus needed to cause a contraction is called the?
The minimum stimulus needed to cause a contraction is called the threshold stimulus. This is the minimal level of stimulation required to activate muscle fibers and initiate a contraction response.
A muscle fiber will not respond to a stimulus until that stimulus reaches what?
A muscle fiber will not respond to a stimulus until that stimulus reaches the threshold level needed to trigger an action potential. This threshold level is the minimum amount of stimulus required to elicit a response from the muscle fiber.
Is conducting stimulus strong enough to generate a nerve impulse?
Yes, a stimulus needs to reach a certain threshold level of strength in order to generate a nerve impulse. This threshold is required to depolarize the cell membrane and initiate the action potential. If the stimulus is not strong enough to reach this threshold, no nerve impulse will be generated.
How does the threshold stimulus influence muscle contraction?
The threshold stimulus is the stimulus required to create an action potential. So any stimulus under this level will not cause muscle contraction, while a stimulus above this level will cause the muscle to contract. The higher the stimulus the more muscle fibers are recruited, and thus the higher the response.
Given that action potentials traveling down the axon of a particular neuron are always the same amplitude how is a stronger stimulus communicated to the next cell in the neural pathway?
A stronger stimulus is communicated to the next cell in the neural pathway by increasing the frequency of action potentials generated by the neuron. A stronger stimulus will trigger action potentials to occur more frequently, which results in a higher frequency of signals being transmitted to the next cell.
