| A | B |
|---|
| voltage | measure of the potential energy generated by separated charge |
| current | flow of electrical charge |
| resistance | hinderance to the flow of charge |
| electrochemical gradient | differences in the concentration of ions across a membrane |
| -70mV | resting voltage of the membrane |
| maintain the electrochemical gradient | chemically gated and voltage gated channels |
| more Na+ | outside the cell |
| more K+ | inside the cell |
| maintains the concentration gradient of sodium ions and potassium ions; 3 Na+ out for every 2 K+ brought in | sodium/potassium pump |
| depolarization | reduction in membrane potential |
| hyperpolarization | membrane potential increases |
| short lived changes in the membrane potential; varying magnitude; decrease in strength over distance | graded potentials |
| brief reversal of the membrane potential; nerve impulse | action potential |
| threshold | depolarization of the membrane to a certain level causing self generating depolarization |
| repolarizing phase | decrease in Na permeability & increase in K permeability |
| undershoot | potassium permeability continues resulting in hyperpolarization |
| depolarizing phase | increase in sodium permeability and reversal of the membrane potential |
| absolute refractory period | ensures that an action potential will not fire too close to another |
| relative refractory period | period following absolute refractory period where the membrane is hyperpolarized from K efflux |
| continuous conduction | unmyelinated axons; slow conduction |
| salatory conduction | myelinated axons; fast conduction, electrical signal jumps from node to node along the axon |
| synapse | a junction where information is transferred from neuron to neuron or from neuron to effector |
| presynaptic | neuron conducting the impulse |
| postsynaptic | neuron receiving the impulse |
| temporal summation | occurs when a neuron receives impulses in rapid fire order |
| spatial summation | occurs when one neuron is stimulated by many other neurons |
