BIOL 4161, Module 2 - Neural Physiology ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
(Boswell) exam with correct answers ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
What is the compound action potential (CAP)?
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
extracellular recording that represents the summed electrical activity produced by a population of neurons ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
within a whole nerve that are brought to threshold by a given stimulus voltage
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
How is the compound action potential "seen"?
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
by extracellular recording electrodes as a wave of outside-negative potential
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
How does the compound action potential behave as it passes by two electrodes?
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
As a CAP passes recording electrode 1 this electrode measures a negative potential compared to the
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
potential measured by recording electrode 2, which the CAP has not yet reached. Accordingly, as the CAP
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
passes recording electrode 1 it is seen as a positive deflection in the recording trace and then as a negative
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
deflection as the CAP passes recording electrode 2. ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
What is the model organism for the neural physiology lab?
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
Xenopus laevis (African clawed frog) ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
What are neurons? ||\\||\\ ||\\||\\
excitable cells that use action potentials (APs) for the rapid transmission of information
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
excitable cells that use action potentials (APs) for the rapid transmission of information
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
neurons
Where are the incoming signals received on a neuron?
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
dendrites (receptive segment) ||\\||\\ ||\\||\\
Once an incoming signal reaches the dendrites, what happens to the signal?
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
transduced into local graded potentials ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
Where are the local graded potentials integrated?
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
axon hillock ||\\||\\
What is the site of AP initiation?
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
axon hillock ||\\||\\
What causes an action potential to be initiated at the axon hillock?
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
An AP will be initiated if summed effect of graded potentials depolarize the membrane past a critical
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
threshold potential ||\\||\\
Once initiated at the axon hillock, where do action potentials travel?
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
propagate along the length of the axon ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
What causes the depolarization stage of action potential?
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
, influx of sodium (opening of voltage gated sodium channels causes sodium to rush inwards)
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
What causes the repolarization phase of action potential?
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
efflux of potassium ions (opening of rectifying voltage-gated potassium channels causes potassium to leave
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
the cell) ||\\||\\
What are nerves? ||\\||\\ ||\\||\\
groupings of neuron axons bundled together by connective tissue ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
What will the extracellular recording electrodes be used to measure?
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
compound action potentials (CAPs) from an isolated sciatic nerve ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
What is a compound action potential? ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
represents the summed electrical activity of the population of neurons triggered to fire an action potential ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
What is the CAP amplitude directly proportional to?
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
the total number of neurons firing and action potential simultaneously
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
What does the LabChart waveform in this experiment represent?
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
the difference in electrical potential between two extracellular recording electrodes (trace value = R2 – R1)
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
Why do CAPs generate a wave of outside negative potential (measured by the extracellular electrodes)?
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
due to the removal of sodium from the surrounding Ringer's Solution (into the sciatic nerve)
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
What is the name of the solution that surrounds the sciatic nerve in this experiment?
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
Ringer's solution ||\\||\\
The greater the number of neurons recruited to fire an AP, the ___ (larger/smaller) the corresponding CAP
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
amplitude will be. ||\\||\\ ||\\||\\
larger
Will a single sub-threshold stimulus trigger an action potential?
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
No, not by itself (an AP is triggered when the membrane potential at the axon hillock is depolarized past the
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
threshold stimulus)
||\\||\\ ||\\||\\
How can sub-threshold stimuli trigger an action potential?
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
Two or more sub-threshold stimuli that occur in quick succession can summate arithmetically to reach
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
threshold and trigger an AP to fire ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
What is temporal summation? ||\\||\\ ||\\||\\ ||\\||\\
occurs when two sub-threshold stimuli elicit a measurable CAP (stimuli occur in quick succession and
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
summate arithmetically to reach a threshold) ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
While we are looking at temporal summation in the frog sciatic nerve, where does temporal summation
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
usually occur? ||\\||\\
at the axon hillock of a neuron
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
What causes the absolute refractory period? During what stages?
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
due to inactivated sodium channels (depolarization and repolarization)
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
(Boswell) exam with correct answers ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
What is the compound action potential (CAP)?
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
extracellular recording that represents the summed electrical activity produced by a population of neurons ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
within a whole nerve that are brought to threshold by a given stimulus voltage
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
How is the compound action potential "seen"?
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
by extracellular recording electrodes as a wave of outside-negative potential
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
How does the compound action potential behave as it passes by two electrodes?
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
As a CAP passes recording electrode 1 this electrode measures a negative potential compared to the
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
potential measured by recording electrode 2, which the CAP has not yet reached. Accordingly, as the CAP
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
passes recording electrode 1 it is seen as a positive deflection in the recording trace and then as a negative
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
deflection as the CAP passes recording electrode 2. ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
What is the model organism for the neural physiology lab?
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
Xenopus laevis (African clawed frog) ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
What are neurons? ||\\||\\ ||\\||\\
excitable cells that use action potentials (APs) for the rapid transmission of information
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
excitable cells that use action potentials (APs) for the rapid transmission of information
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
neurons
Where are the incoming signals received on a neuron?
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
dendrites (receptive segment) ||\\||\\ ||\\||\\
Once an incoming signal reaches the dendrites, what happens to the signal?
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
transduced into local graded potentials ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
Where are the local graded potentials integrated?
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
axon hillock ||\\||\\
What is the site of AP initiation?
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
axon hillock ||\\||\\
What causes an action potential to be initiated at the axon hillock?
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
An AP will be initiated if summed effect of graded potentials depolarize the membrane past a critical
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
threshold potential ||\\||\\
Once initiated at the axon hillock, where do action potentials travel?
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
propagate along the length of the axon ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
What causes the depolarization stage of action potential?
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
, influx of sodium (opening of voltage gated sodium channels causes sodium to rush inwards)
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
What causes the repolarization phase of action potential?
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
efflux of potassium ions (opening of rectifying voltage-gated potassium channels causes potassium to leave
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
the cell) ||\\||\\
What are nerves? ||\\||\\ ||\\||\\
groupings of neuron axons bundled together by connective tissue ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
What will the extracellular recording electrodes be used to measure?
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
compound action potentials (CAPs) from an isolated sciatic nerve ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
What is a compound action potential? ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
represents the summed electrical activity of the population of neurons triggered to fire an action potential ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
What is the CAP amplitude directly proportional to?
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
the total number of neurons firing and action potential simultaneously
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
What does the LabChart waveform in this experiment represent?
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
the difference in electrical potential between two extracellular recording electrodes (trace value = R2 – R1)
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
Why do CAPs generate a wave of outside negative potential (measured by the extracellular electrodes)?
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
due to the removal of sodium from the surrounding Ringer's Solution (into the sciatic nerve)
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
What is the name of the solution that surrounds the sciatic nerve in this experiment?
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
Ringer's solution ||\\||\\
The greater the number of neurons recruited to fire an AP, the ___ (larger/smaller) the corresponding CAP
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
amplitude will be. ||\\||\\ ||\\||\\
larger
Will a single sub-threshold stimulus trigger an action potential?
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
No, not by itself (an AP is triggered when the membrane potential at the axon hillock is depolarized past the
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
threshold stimulus)
||\\||\\ ||\\||\\
How can sub-threshold stimuli trigger an action potential?
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
Two or more sub-threshold stimuli that occur in quick succession can summate arithmetically to reach
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
threshold and trigger an AP to fire ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
What is temporal summation? ||\\||\\ ||\\||\\ ||\\||\\
occurs when two sub-threshold stimuli elicit a measurable CAP (stimuli occur in quick succession and
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
summate arithmetically to reach a threshold) ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
While we are looking at temporal summation in the frog sciatic nerve, where does temporal summation
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
usually occur? ||\\||\\
at the axon hillock of a neuron
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
What causes the absolute refractory period? During what stages?
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
due to inactivated sodium channels (depolarization and repolarization)
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
