quiz 3 Flashcards
what type of trnasport is flow of ions thru and open channel
passive by diffusion
what allows na+ ions to diffuse across cell membrane
open NA+ channels, Electrical gradient , NA+ conc gradient
what is responsible for changes in membrane resistance over time
opening and closing of ion channels changes the membrane resistance
what must happen to get an action potential started
the membrane must depolarize to a certain threshold potential to permit opening of voltage gated NA+ channels
Electric signaling in neurons follows ohms law, (V= R*I) what represents resitance,
Rm- membrane resistance in the form of the cell membrane with embedded ion channels
eq potential for litium = +50mv
membrane potential is 0mv
open lithium channes
which way will Li ions move
Into the cell
how is information encoded in an action potential
frequency of AP’s
in ohm’s law what represents current
Im- form of flow of ions across membrane
E of Li= 50
Vm=0
open li channels
which direction will LI move
into cell- vm moves toward E
a neuron at rest has a Vm of -65mv, which side of membrane is the one with negative chare
inside of cell is negative compared to outside
why are graded potentials not suited fro long distance info transmission in neurons
graded potentials lose strength over distance. action potentials do not lose strength and can travel long distances without decrement
how is information about stimulus intensity encoded in graded potentials? action potentials?
amplitude of GP’s, frequency of AP’s
why do we care about knowing Equilibrium potentials of ions
what is goldren rule that allows us to apply E to answer questioons
allow us to predict direction of ion flow
ions will always flow in direction that brings VM closer to E
