The action potential Flashcards
what are muscle spindles
stretch receptors of skeletal muscle
what happens when stretch the mechanoreceptors
opening of Na channels causing receptor potential
what type of potential are receptor potentials
graded - good for strength coding
what happens to receptor potentials over space
decremental - decrease
what does action potential begin
spike initiation zone
how is info coded in action potential
frequency and pattern of AP
5 phases of an AP
- resting
- rising
- overshoot
- falling (repolarizing)
- hyperpolarization
what is AP threshold
minimum voltage that must be reached to initiate - 55mV
what happens with more depolarization
more frequent AP
what limits AP frequency
refractory period (absolute or relative)
what opens with AP
Na and K channels
which channel opens faster
Na, and K sustains over depolarization
what are 3 states of Na channel
- resting
- activated
- inactivated
what reverses inactivation of Na channel
regaining -70
what happens during threshold phase
inward Na> outward L
