Flashcards
Excitable Cells
Flashcards do conjunto (15)
- 1What is Vm?Resting membrane potential
- 2Origin of VmUneven distribution of ions across a membrane
- 3What maintains Vm?Na+/K+ pumps
- 4Nernst limitationsDeals with 1 ion at a time and assumes it's in electrochemical equilibrium
- 5Nernst EquationEx = 61og[X]o/[x]i mV
- 6GHK equationVm = pk[K+]out+p(Na)[Na+]out+pCl[Cl-]in
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pK[K+]in + pNa[Na+]in+pCl[Cl-]out - 7Why is Cl in/out?As it has a negative valence
- 8What is conductance and indirect measurement of?Permeability of a channel when a specific voltage is applied to a membrane
- 9How does an uneven distribution of charge lead to an action potential?When the influx of Na+ surmounts the rate at which the cell can release K+ to compensate then an action potential is triggered and Vm becomes a function of [Na+]'
- 10terminationChannel inactivation of Na+ halts inward flow of Na+
K+ passively flows out, repolarising the cell. - 11Why is there an undershoot?As K+ channels open and close slowly, the increased K+ permeability is slow to cease
- 12What is ARP?Absolute refractory period
- 13Yeah, but what IS ARP?Period after an AP in which channels are deactivated and can't be opened
- 14What is RRP?After ARP Na+ channels begin to recover from inactivation
Difficult to trigger an AP as Na+ channels still recovering - 15What is capacitance an indirect measurement of?Voltage passing through a resistor
Like protestors running through a riot squad, some of them will be pushing against the riot men whilst the few that break through are the conductance
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- FlashCards sobre Excitable Cells, criado por J yadonknow em 28-05-2018.
- Criado por
- J yadonknow
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