<P> An action potential is a spike of both positive and negative ionic discharge that travels along the membrane of a cell . The creation and conduction of action potentials represents a fundamental means of communication in the nervous system . Action potentials represent rapid reversals in voltage across the plasma membrane of axons . These rapid reversals are mediated by voltage - gated ion channels found in the plasma membrane . The action potential travels from one location in the cell to another , but ion flow across the membrane occurs only at the nodes of Ranvier . As a result , the action potential signal jumps along the axon , from node to node , rather than propagating smoothly , as they do in axons that lack a myelin sheath . The clustering of voltage - gated sodium and potassium ion channels at the nodes permits this behavior . </P>
<P> An action potential is a spike of both positive and negative ionic discharge that travels along the membrane of a cell . The creation and conduction of action potentials represents a fundamental means of communication in the nervous system . Action potentials represent rapid reversals in voltage across the plasma membrane of axons . These rapid reversals are mediated by voltage - gated ion channels found in the plasma membrane . The action potential travels from one location in the cell to another , but ion flow across the membrane occurs only at the nodes of Ranvier . As a result , the action potential signal jumps along the axon , from node to node , rather than propagating smoothly , as they do in axons that lack a myelin sheath . The clustering of voltage - gated sodium and potassium ion channels at the nodes permits this behavior . </P>
where are voltage gated sodium channels concentrated in myelinated axons
where are voltage gated sodium channels concentrated in myelinated axons
plasma membrane
plasma membrane