Biopsych Exam 2: Action Potentials and Synapses

potassium/K⁺

ion with highest permeability at rest

1) Na⁺ channels open 2) K⁺ channels open 3) Na⁺ channels close 4) K⁺ channels close

steps in an action potential

absolute refractory period

stimulation cannot elicit another action potential because Na⁺ channels are deactivated

relative refractory period

stimulation can elicit another action potential but it is harder because the membrane is hyperpolarized

temperature, acidity, mechanical, electrical, chemical

types of ion channel gating

myelinated and large

fastest type of axon

what EPSP stands for

excitatory postsynaptic potential

excitatory postsynaptic potential (EPSP)

depolarization of cell membrane that makes action potential more likely

what IPSP stands for

inhibitory postsynaptic potential

inhibitory postsynaptic potential (IPSP)

hyperpolarization of cell membrane that makes action potential less likely

synapse

the gap between one neuron and another where neurotransmitters are released and bound

deactivation of neurotransmitters

diffusion, deactivating enzymes, reuptake

Ca²⁺

ion that is required for the release of neurotransmitters

electrical synapse

pore between 2 cells that very small things (ions) can pass through; allows for fast propagation of electrical signals

ionotropic receptor

ion channel that is opened/closed by binding of neurotransmitters

metabotropic receptor

receptor that causes a cascade of events that opens a different ion channel upon binding of neurotransmitter