Medical Definition of antioxidant. : any of various substances (as beta-carotene, vitamin C, and alpha-tocopherol) that inhibit oxidation or reactions promoted by oxygen and peroxides and that include many held to protect the living body from the deleterious effects of free radicals.
An action potential is a very rapid change in membrane potential that occurs when a nerve cell membrane is stimulated. Specifically, the membrane potential goes from the resting potential (typically -70 mV) to some positive value (typically about +30 mV) in a very short period of time (just a few milliseconds).
The action potential is. â¢ a wave of electricity that travels down the axon of neuron â¢ from the cell body to the axon terminals This wave of electricity is actually a brief change in the resting membrane potential of the neuron â¢ from -70mv to +35mv Then the membrane returns to its resting potential of -70mv. î î î. Briefly opening more membrane gates for Na+ and then for K+ â¢ Thus making the neuron cell membrane o More permeable first to Na+ o Then to K+ â¢ This causes a change in the numbers of plus charges inside and outside the cell membrane o Changing the cell membrane potential.