Part A Types of postsynaptic potentials The binding of neurotransmitter to ligand gated ion channels in the postsynaptic membrane causes these channels to open As soon as the neurotransmitter is removed from the synaptic cleft the ligand gated ion channels close In the brief time these channels are open ions are able to diffuse across the postsynaptic membrane down their electrochemical gradient The result is a postsynaptic potential a brief change in the membrane potential of the dendrites and cell body of the postsynaptic cell There are two types of postsynaptic potentials excitatory postsynaptic potentials EPSPs and inhibitory postsynaptic potentials IPSPS An EPSP is excitatory because it makes it more likely that the axon of the postsynapti cell will trigger an action potential Conversely an IPSP is inhibitory because it makes it less likely that the axon of the postsynaptic cell will trigger an action potential Sort the phrases into the appropriate bins depending on which type of postsynaptic potential they describe If a phrase describes both types of potentials drag it to the both bin View Available Hint s hyperpolatzes the postsynaptic membrane depolarizes the postsynaptic membrane brings the postsynaptic membrane potential closer to threshold excitatory postsynaptic potential EPSP moves the postsynaptic membrane potential farther away from threshold sa graded potential results from the movement of im K ions out of the postsynaptic cel inhibitory postsynaptic potential IPSP results from the movement of m Na ions into the postsynaptic cell Reset Help both