Action Potentials Flashcards
Why are AP’s imp for dentists
for local anaesthesia and pain etc
what are the diffenret chemical singling of the body
short distance - synapse
long distance - hormones
how fast is the chemical singling in the body
relatively slow
what are the types of electrical signalling in the body
graded potentials
AP’s
what are graded potentials
short distance
vary
fizzle out at nerve endings
what are AP’s
long distance
all or none
fast 120m/s
is the nerve membrane a good insulator
no poor as phospholipids are leaky and in aq enviro
is the cytoplasm good conductor
no poor
what happens to signals in nerves over 2-3mm and what is this due to
decays
due to high resistance and poor insulation
what is used in nerves to help with propagations of signals
AP’s
what is a resting mem pot
Separation of opposite charges across a membrane
what causes a rest mem pot
perm of key ions
corn grad for key ions
gradients maintained by active transporters
do all cells have rest me pot
yes
what are excitable cells
nerve and muscle
what are the extra/intracellular conc and relative perm of Na, K an anion
Na
extra - 150
intra - 15
RP - 1
K
extra - 5
intra - 150
RP - 25-30
anion
extra - 0
intra - 65
RP - 0
roughly explain the Na/K pump
uses ATP
transports 3 Na out
2 K in
helps maintain conc grads
si the mem perm or imperm to K
perm at rest
what is the electrochem gradient for K
chemical - k out
electrical - protein anions cant flow out so k attracted in
what is the nernst value for K equilibrium potential
-90mV
what si the mem at rest like toward Na
much less perm to Na