(Original post by arvin_infinity)
Wondered why larger diameter of axon causes greater speed of transmission.
MS: "Less leakage of ions from wider axon"
Didn't quite get why less leakage.
Basically, this is my interpretation after researching it, as I was confused like you are. Essentially what books say is the larger the diameter the faster an impulse is conducted because less leakage and ions have less resistance to movement.
I can only expand on my latter point. As the axon is wider, ions collide less when either being actively moved by the sodium-potassium pump or diffusing through the sodium or potassium channels, and so as there is less resistance (LIKE IN GEL ELECTROPHORESIS) the ions move faster, meaning adjacent regions depolarise at a faster rate i.e. impulse conducted at higher rate