Physiology - Action potentials Flashcards
MS arises due to damage of the..
a. pottasium channels
b. myelin
c. sodium channels
d. sodium pottassium pump
b.myelin
what is it is known as when no stimulus is effective
a,inactive
b. hyperpolarisation
c. absolute refractory
d. relative refractory
c.refractory
in what period can a v large stimulus generate an AP
a,inactive
b. hyperpolarisation
c. absolute refractory
d. relative refractory
d.relative refractory
what happens to membrane conductance when permeability increases and therefore resistance decreases
a. increases
b. decreases
increases
at peak of AP membrane potential approaches ..
A. Ek
b.Ena
b.Ena
changes in membrane permeability are due to..
a. sodium pottasium pump
b. pottasium leak channels
c. voltage gated ion channels
c. voltage gated ion channels
what state are voltage dependent channels at rest
a. open
b. closed
b.closed
what does continued depolarisation do to the sodium channel
a. activates it
b. inactivates it
b.inactivates it
which channels activate more slowly
a. sodium
b. pottasium
b.pottasium
which type of channel is responsible for the relative refractory period
a. sodium
b. pottasium
b.pottasium
what property of neruron membranes ensure unidirectional flow
a. self propagation
b. refractory periods
c. local circuits
b.refractory periods
what happens to velocity of propagation as axon diametre increases
a. increase
b. decrease
a.increase
what happens to electrical resistance as axon diametre increases
a. increase
b. decrease
b.decrease
where are APs generated in a myelinated neuron
a. nodes of ranvier
b. myelin sheath
a.nodes of ranvier
slow pain fibres and autonomic
motor nerves have what structure
a. small myelinated
b. small unmyelinated
c. large myelinated
b.small unmyelinated
