Dr. Parker Flashcards
Antidromic
The opposite direction from normal for action potential propagation.
What does orthodromic mean?
The direction in which an action potential travels normally.
What does local anasthesia block?
Sodium channels on axons.
What is the speed of an action potential?
Roughly 10-100 m/s
What determines action potential speed?
The resistance (given by 1/r^2 of the axon radius), and the capacitance (given by r). As the radius increases the resistance decreases exponentially and the capacitance increases linearly, so overall speed increases linearly.
What does myelin do?
Mylein increases the distance between the two “capacitor plates”, decreasing the capacitance of the axonal membrane and thus increasing action potential travel speed.
What does saltatory transmission mean?
“Jumping” transmission, used to describe myleinated axon action potential propagation.
