Lecture 2 Flashcards
(52 cards)
neurophysiology
study of life processes of neurons
anion
negatively charged
cation
positively charged
microelectrode
used to show the interior was mroe negative than exterior in membrane
resting potential inside membrane
-50 to -80 mV
ion channels
allow ions to pass through
leaky potassium channels
open all the time
neurons are
selectively permeable
diffusion
movement along concentration gradient
electrostatic pressure
movement of ions to oppositely charged areas
sodium potassium pump
3 sodium out for 2 k+ in
equilibrium potential
electrical charge that balances the opposing forces –> concentration gradient and electrostatic potential
axon hillock
membrane potential originates just after here
hyperpolarization
increased membrane potential –> charge moves even further from zero
depolarization
interior becomes less negative
graded response
change in potential –> greater the stimulus the greater the response
local potential
as potnetial moves further away from point of stimulation, it decreases
threshold
depolarization to about -40 mV that triggers action potential
all or none porperty
action potential either fires or it doesn’t –> amplitude of action potential is not relates to stimulus size
after potential
small changes in membrane potential after action potential
voltage gates channels
change shape and open in response to changes in charge *like depolarization
absolute refractory period
no action potentials can be produced
relative refractory phase
only strong stimulation can produce action potential
conduction velocity
speed of propagation of action potentials vary with axon diameter
