Chapter 15.2: Generation and Transmission of Action Potentials

When nerve impulses are generated, they result in action potentials across the membrane of an axon. These action potentials are due to the action of the sodium-potassium pump, sodium and potassium channels as well as sodium and potassium voltage-gated channels. In this video, I explain how action potentials are generated and transmitted and also highlight how the different activities in the membrane of the axon fit on the potential difference graph that shows how potential difference across the membrane of the axon changes with time. The key parts of this graph are resting potential (-70mV), threshold potential (-50mV), depolarization (maximum of +30mV), repolarization (return to resting potential), and hyperpolarization ( a dip in membrane potential due to the potassium gated channels not closing quickly enough). It is important to note that the strength of a stimulus does not result in bigger action potentials; rather it results in more frequent action potentials across the membrane of the axon. Please post any questions or comments in the chat below!