This video describes the steps of an action potential, refractory periods, and how they compare with graded potentials, as well as events at the synapse.
Time Stamps
Action Potentials, the synapse, graded potentials
Ion concentrations around cells 0:15
Polarization 4:07
Voltage-gated and chemically-gated ion channels 4:40
Pre and postsynaptic neurons 6:14
Action potentials 8:05
Summary of steps in an action potential 14:25
Sodium inactivation gate and refractory periods 15:44
Saltatory conduction 19:35
The synapse 21:40
Graded potentials 23:44
Action potential-Graded potential summary chart 29:35
Images from my Textbook: Human Biology, Anatomy and Physiology for the health Sciences
Images from Pixabay Royalty free stock images
