1-5-A Neuronal Action Potential Flashcards
1) Refraction Periods = (time it takes for neuron_________) is ______ [Fast/slow] so that ________
2) Cardiac Ventricle Refractory period is ______[shorter/Longer] than others. Why is this?
3) Name the 3 Cells that have Refractory Periods?
1) Refraction Periods (time it takes for neuron to start from resting potential and get back to resting potential) is FAST so that 1 AP can occur before the next starts!
2) Cardiac Ventricle Refractory period is longer to protect heart from additional electrical activity
3) Occurs in Motor Neurons / Skeletal Muscle / Cardiac Ventricle
1) [Subthreshold local responses] = small responses to ________ ________ that ________
2) When cell is depolarized to threshold = ______ ______ OCCURS! —> ___ Channels open and ___ rushes INTO cell ______[passively/Actively]
1) [Subthreshold local responses] = small responses to depolarizing currents that bring neurons closer to [AP threshold]
2) When cell is depolarized to threshold = ACTION POTENTIAL OCCURS! —> Na+ Channels open and Na+ rushes INTO cell passively
A: [Space Length Constant] = distance a ______ ______ can travel to the ______ before ______
B: LARGE Diameter axons= ______[higher/lower] internal and membrane resistance = ______ [longer/shorter] wavelength = ______[faster/slower] conduction
B2: ______ resistance decreases more than ______ resistance
So if you DEC ______ resistance you will INCREASE wavelength
A: [Space Length Constant] = distance a subthreshold depolarization can travel to the next membrane segment b4 dying out
B: LARGE Diameter axons= LOW internal and membrane resistance = LONGER wavelength = faster conduction
B2: {Ri} decreases more than {Rm}.
So if you DEC {Ri} you will INC wavelength
1) At Rest: INNER CELL = ______[positive/negative] and the Outer Cell = ______ [positive/negative]
2) Once a PART of the membrane is depolarized it becomes ______ from ______ state. What does this result in?
3) Local current flow= activates ______ channels to ______ the next membrane segment —> ______ ______ in the resting membrane
4) ______ ______ are [ALL OR NONE RESPONSE]. What does this mean?
1) At Rest: INNER CELL = negative - - - - -
outer cell = + + + “positively cold outside”
2) Once a PART of the membrane is depolarized it becomes reversed from resting state and potential difference between the 2—>[local current flow] .
3) [Local current flow= activates Na+ channels to depolarize the next membrane segment —>AP in the resting membrane
4) Action Potentials are [ALL OR NONE RESPONSE] = A stimulus will either {elicit} an AP or {fail to elicit} an AP…no inbetween
B: REPOLARIZATION of AP comes from 2 things. What are they?
In this case ___ rushes OUT of the Cell and Cell becomes more ______[+/-]
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C: ______ can ONLY be closed/DEactivated by repolarization of the membrane potential
D: When channels are open, Na+ and K+ enter/leave cell ______ because they’re going down their gradient
B: REPOLARIZATION of AP comes from
1. [Na+ channels CLOSING] = “inactivation”
2. delayed INC of [K+ channels opening]
= K+ rushes OUT = Cell becomes more negative
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C: [K+ channels] can ONLY be closed/DEactivated by repolarization of the membrane potential
D: When channels are open, Na+ and K+ enter/leave cell PASSIVELY because they’re going down their gradient
[M Gate] and [H-gate] regulate ____ movement!
- ## Activated: M Gate = ______ / H-gate = ______ –>___ influx*INactivated: M Gate = ______ / H-gate = ______
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B: [Repolarization/____[+/-] membrane voltage] is what allows these channels to ___________
[M Gate] and [H-gate] regulate Na+ movement!
- ## Activated: M Gate = OPEN / H-gate = OPEN –>Na+ influx*INactivated: M Gate = OPEN / H-gate = closed
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B: [Repolarization/(-) membrane voltage] is what allows these channels to RESET from Inactivated –(back to)—> Resting
- [Na+ channels] are both ______ and ______ -dependent activated
2) Regenerative Depolarization= Na+ rushing into cell down both its ______ and ______ gradient to depolarize membrane potential to ______–(leads to)—>_____ channels opening and ______ feedback
3) What is the basis for refractory periods
- [Na+ channels] are both Time and Voltage -dependent activated
2) Regenerative Depolarization= Na+ rushing into cell down both its CONCENTRATION and ELECTRICAL gradient to depolarization membrane potential to it specific electrical potential–(leads to)—>more Na+ channels opening/positive feedback
3) Voltage-dependent INactivation of Na+ channels is the basis for refractory periods
A:[T or F]
Different neuronal cells have different K+ channels
B: [T or F]
K+ channels have multiple INactivation parameters
A: TRUE
Different neuronal cells DO have different K+ channels
B: FALSE
K+ channels have NO INactivation gate
A: K+ channels are ______ selective channels made of ___ ______. Although they exhibit ______ and ______-dependent ACTIVATION they do NOT have any ______ ______. This means that (unlike __) once open K+ channels remain OPEN until they’re deactivated with ______
B: [K+ channels] are activated/opened when ______ from ______ occurs . = ______- dependent
C: When K+ ______ rushes ______ of cell—> toward its specific potential this eventually causes ______
A: K+ channels are HIGHLY selective channels made of 4 subunits. Although they exhibit time and voltage-dependent ACTIVATION they do NOT have any INactivation gates—-> (unlike Na+) once open K+ channels remain OPEN until they’re deactivated with repolarization
B: [K+ channels] are activated/opened when [AP upstroke] from Depolarization occurs . = Voltage- dependent
C: When K+ PASSIVELY rushes out of cell—> toward its specific potential = hyperpolarizes
______-dependent activation of K+ channels is Delayed/Slower than Na+
Voltage-dependent activation of K+ channels is Delayed/Slower than Na+
A: What’s the difference between Absolute and Relative Refractory Period?
B: Refractory periods are based on ______-dependent features of ______ channels! ______ channels inactivate at ______ voltages and become unavailable = ______ Refractory Period
After REpolarization ______ channels recover from INactivation and become available again but requires STORNG stimulus = ______ Refractory Period
C: C: H-gate is ______[open/closed] during Absolute Refractory Period
Absolute Refractory Period (ARP): TIME in which a stimulus can NOT create another Action Potential
vs.
Relative Refractory Period(RRP:) TIME during which ONLY A STRONG stimulus can elicit another Action Potential but will be weak!
B: Refractory periods are based on voltage-dependent features of Na+ channels! Na+ channels inactivate at POSITIVE voltages and become unavailable = ARP
After REpolarization Na+ channels recover from INactivation and become available again but requires STORNG stimulus = RRP
C: H-gate is CLOSED!! During ARP!
A: Ca+ modulates Na+ channel activity by altering ______ ______ ______
B: Name the 2 conditions that can metabolically cause HYPERREFLEXIA
C: Blowing off [-CO2] —> ______ plasma Ca+—> ______ extracellular membrane Positivity–> DEC [___ channel ______] —> ______[easier/harder] neuronal excitability!
A: Ca+ modulates Na+ channel activity by altering membrane surface charge
B: HYPERREFLEXIA
- HYPERventilation
- HypOcalcemia
blowing off [-CO2] —> DEC plasma Ca+—>DEC extracellular membrane Positivity–> DEC [Na+ channel activation threshold level] —>easier neuronal excitability!
A: Ca+ modulates Na+ channel activity by altering ______ ______ ______
B: Name the 2 conditions that metabolically cause hypOreflexia
HIGH -CO2—-> ______ Plasma Ca+—>extracell membrane is MORE ______[+/-] —> INC [___ channel ______]—>__-gate closes and ___channels are less available —–> ______[easier/harder] to excite neurons :-(
A: Ca+ modulates Na+ channel activity by altering membrane surface charge
B: hypOreflexia
- hypOventilation
- Hypercalcemia
HIGH -CO2—-> INC Plasma Ca+—>extracell membrane is MORE + —> INC [Na+ channel activation threshold level]—>H-gate closes and Na+ channels are less available —–> HARDER to excite neurons :-(
- Normal Extracellular K+ levels is between ____
2) HYPERkalemia —> _____ Positivity of Resting Membrane Potential —> ___-gate closes and ____ channels are less available
3) HYPERkalemia causes Conduction to go ______[Faster/slower]. Name 2 sx
- Normal Extracellular K+ levels is between 3 and 5
2) HYPERkalemia —> INC Positivity of Resting Membrane Potential —> H-gate closes and Na+ channels are less available
3) HYPERkalemia causes Conduction to SLOW =
•muscle weakness
•slow mentation
A: ______ axons are 100 x bigger in Diameter than ______ axons.
B: DESPITE THIS… ______ AXONS HAVE BETTER CONDUCTION VELOCITY because _______________
C: Saltatory Conduction = “______” from [__ ______ concentrated] ______ to ______
D: Internodal distance between 2 ______ = ____ mm
E: THERE ARE NO [___ channels] UNDER MYELIN SHEATH
A: UNmyelinated axons are 100 x bigger in Diameter than myelinated axons.
B: DESPITE THIS…MYELINATED AXONS HAVE BETTER CONDUCTION VELOCITY because myelin sheath INC membrane resistance
C: Saltatory Conduction = “jumping” from [Na+ channel Rich] [Node of Ranvier] to [Node of Ranvier]
D: Internodal distance between 2 [Node of Ranvier] = 1-2 mm
E: THERE ARE NO [Na+ channels] UNDER MYELIN SHEATH
