impulses Flashcards
(5 cards)
1
Q
how does the pacinian corpuscle cause a nerve impulse (3)
A
pressure applies deforms it
stretch-mediated Na+ channels open, ion moves down conc grad
potential difference becomes positive forming a generator potential
2
Q
explain how resting potential is maintained (3)
A
higher conc of K in and Na out
membrane more permeable to K
Na transported out, K in
3
Q
why is speed of transmission faster in myelinated axon (3)
A
myelination provides insulation
saltatory conduction
depolarisation at nodes
4
Q
why do inhibitors have effects on resting potential
A
less ATP produced
less active transport
electrochemical gradient not maintained
4
Q
how does Cl- in the post synaptic membrane inhibit the neurone (3)
A
neurone becomes hyperpolarised
more Na+ required
for action potential
