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When a stimulus is sufficiently great enough to change the membrane potential and propagate an action potential it is called?
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∙ 12y ago
recruitement
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∙ 12y ago
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WhatConversion of a stimulus into a generator potential is?
Receptor potential, a type of graded potential, is the transmembrane potential difference of a sensory receptor. A receptor potential is often produced by sensory transduction. It is generally a depolarizing event resulting from inward current flow. The influx of current will often bring the membrane potential of the sensory receptor towards the threshold for triggering an action potential. A receptor potential is a form of graded potential, as is a generator potential. It arises when the receptors of a stimulus are separate cells. An example of this is in a taste bud, where taste is converted into an electrical signal sent to the brain. When stimulated the taste bud triggers the release of neurotransmitter through exocytosis of synaptic vesicles from the presynaptic membrane. The neurotransmitter molecules diffuse across the synaptic cleft to the postsynaptic membrane. A postsynaptic potential is then produced in the first order neuron, and if the stimulus is strong enough to reach threshold this may generate an action potential which may propagate along the axon into the central nervous system
What is a simple neural receptor?
A receptor (protein) on a neuron that receives stimulus (light, pressure, chemical...etc). The stimulus generates a receptor potential (local disturbance/slight depolarization in membrane potential).
Why is the resting membrane potential the same value in both the sensory neuron and the interneuron?
Because it didnt have a stimulus to activate depolarization
Why does the polarity of a cell membrane reverse during an action potential?
During an action potential the neuron receives a stimulus causing the cell membrane to become more permeable to sodium than potassium, calling the polarity to change.
Minimum level of stimulation required to trigger a neural impulse?
An action potential needs to occur to trigger the neurons but the action potential depends on whether a stimulus is able to bring the membrane potential to a certain level termed the THRESHOLD. This threshold is about -55 mV for most neurons, but the stimulus needs to bring the membrane potential to this certain level or it will not be triggered. Relating to the ALL-OR-NONE PRINCIPLE, which if the threshold is not acquired then an action potential will not occur but once a stimulus is strong enough to depolarize (making the inside of the cell less negative going from -70 mV to -55 mV) it will trigger. The resting potential is -70 mV which the stimulus needs to bring it up to -55mV.
WhatConversion of a stimulus into a generator potential is?
Receptor potential, a type of graded potential, is the transmembrane potential difference of a sensory receptor. A receptor potential is often produced by sensory transduction. It is generally a depolarizing event resulting from inward current flow. The influx of current will often bring the membrane potential of the sensory receptor towards the threshold for triggering an action potential. A receptor potential is a form of graded potential, as is a generator potential. It arises when the receptors of a stimulus are separate cells. An example of this is in a taste bud, where taste is converted into an electrical signal sent to the brain. When stimulated the taste bud triggers the release of neurotransmitter through exocytosis of synaptic vesicles from the presynaptic membrane. The neurotransmitter molecules diffuse across the synaptic cleft to the postsynaptic membrane. A postsynaptic potential is then produced in the first order neuron, and if the stimulus is strong enough to reach threshold this may generate an action potential which may propagate along the axon into the central nervous system
What is local response?
Local responce is a small change in membrane potential caused by a subthreshold stimulus.
What is a simple neural receptor?
A receptor (protein) on a neuron that receives stimulus (light, pressure, chemical...etc). The stimulus generates a receptor potential (local disturbance/slight depolarization in membrane potential).
Why is the resting membrane potential the same in both the sensory neuron and the interneuron?
Because it didnt have a stimulus to activate depolarization
Why is the resting membrane potential the same value in both the sensory neuron and the interneuron?
Because it didnt have a stimulus to activate depolarization
Why does the polarity of a cell membrane reverse during an action potential?
During an action potential the neuron receives a stimulus causing the cell membrane to become more permeable to sodium than potassium, calling the polarity to change.
What is the cause of the relative refractory period?
The Refractory period is when a second action potential is possible, but unlikely; second action potential only if the stimulus is sufficiently strong. The refractory period helps to prevent backflow of Sodium.
Minimum level of stimulation required to trigger a neural impulse?
An action potential needs to occur to trigger the neurons but the action potential depends on whether a stimulus is able to bring the membrane potential to a certain level termed the THRESHOLD. This threshold is about -55 mV for most neurons, but the stimulus needs to bring the membrane potential to this certain level or it will not be triggered. Relating to the ALL-OR-NONE PRINCIPLE, which if the threshold is not acquired then an action potential will not occur but once a stimulus is strong enough to depolarize (making the inside of the cell less negative going from -70 mV to -55 mV) it will trigger. The resting potential is -70 mV which the stimulus needs to bring it up to -55mV.
Do action potentials always have the same amplitude and the same duration?
Yes, this is due to the all or nothing law that neurons follow: "an excitable membrane either responds to a stimulus with a maximal action potential that spreads nondecrementally throughout the membrane, or it does not respond with an action potential at all." "
How do synapse help ensure one way transmission?
Absolute refractory period (time which local area of the membrane has surpassed the threshold potential and will not respond to any stimulus).
How is one-way conduction at synapses ensured?
Absolute refractory period (time which local area of the membrane has surpassed the threshold potential and will not respond to any stimulus).
What is the neural impulse generated by the movement of positively charged atoms in and out of channels in the axon's membrane?
simple automatic, inborn response to a sensory stimulus
