Ch 7 - Action Potential Flashcards
ap is propagated with the same blank and blank along the whole length of the nerve or muscle cell
size, shape
action potential is a rapid and momentary change in blank of a nerve or muscle cell when excited resulting the transmission of a blank signal
membrane potential, electric
property of ap that limits the frequency of them
refractory period
the ap is blank so it does not lose strength of signal
self regenerative
ap results from increase in ionic blank
ionic conductance
a voltage clamp blank the voltage by not allowing the blank to change
fixes, membrane potential
the blank maintains the command voltage by sending current out if there is current coming in and vice versa
feedback amplifier
a sudden hyperpolarization results in a transient blank current but not blank currents
capacitative, ionic
the blank current is very short lived
capacitative
resting ion channels are aka blank channels
leakage
no blank channels have net current during hyperpolarization, but they have a net current during blank
leakage, depolarization
current above 0 is blank
outward
voltage gated sodium and potassium channels open when blank depolarization signal is given to the cell
large
to study the current of only K+ ions, sodium ions were replaced with a blank so only the potassium flowed
impermeable choline ion
ttx is
tetradotoxin
ttx blocks blank ion channels
sodium voltage gated
ttx is produced by blank
puffer fish
these two block sodium channels
ttx, saxitoxin
these two block potassium channels
aminopyridine, TEA
TEA has a blank affinity so it takes blank of the drug to have an effect
low, a lot
dominant ion on inside of cell
potassium
with a prolonged depolarization signal, blank channels NEVER close but blank do
potassium, sodium
measurements of gna and gk at various levels of membrane potentials reveal two functional similarities and two differences
2 similarities
- both open in response to depolarization
- as size of depolarization increases probability R rate of opening of Na and K channels increase
2 differences
- (rate of opening) sodium channels open more rapidly at depolarizing potentials than potassium channels
- (response to prolonged depolarzation) when depolarization is maintained for a long period of time, sodium channels begin to close which causes a decreased inward current…. potassium channels remain open
process by which sodium channels close during a prolonged depolarization is termed blank
inactivation
channel is only open during the brief period of time when blank gates are open
activation/inactivation
activation gate is closed at blank
resting membrane potential
activation gate opens by blank signal
depolarization
inactivation gate is open at blank
resting membrane potential
inactivation gate closes during
prolonged depolarization
