ion channels pt.2

leak channel (passive) stimulus to open/close

alway opens

leak channel comment

help establish RMP

chemically gated Na + channel stimulus open/close

excitatory chemicals

chemically gated Na+ channel comment

depolarize to threshold

chemically gated K+ channel stimulus to open/close

inhibitory chemicals

chemically gated K+ channel comment

hyperpolarize

voltage gated Na+ channel stimulus to open/close

open @ = -60mV, close @= +30mV

voltage gated Na+ channel comment

rapid depolarization of action potential

voltage gated K+ channel simulus to open/close

open @= +30mV, close @= -70mV

voltage gated K+ channel comment

@ synaptic knob

mechanically gated channel stimulus to open/close

mechanically gated channel comment

threshold

voltage necessary to begin opening voltage gated channels

graded potential

small localized change in the RMP

subthreshold potential

membrane potential change in a neuron that is not strong enough to trigger an action potential

depolarization

if the NT opens a sodium channel, sodium ions will ENTER the cell, the neuron will become POSITIVE inside.

in depolarization when a neuron depolarizes or becomes excited it will have

EPSP

hyperpolarization

If the NT opens a potassium channel, potassium ions will EXIT the cell. The neuron will become NEGATIVE

In hyperpolarization when a neuron hyperpolarize it will

IPSP

Summation

several stimulations added together

temporal summation

results from continuous stimulation of a single synapse to add either EPSP or IPSP together.

spatial summation

results from simultaneous stimulation of numerous synapses to add either EPSP or IPSP’s together