[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.


+rep

[007007]

With a larger diameter, there is less resistance. Hence increased conduction velocity

This was posted from The Student Room's Android App on my GT-I9100

[arvin_infinity]

(Original post by 007007)
With a larger diameter, there is less resistance. Hence increased conduction velocity

This was posted from The Student Room's Android App on my GT-I9100

Well I do understand that but I dind't understand the mark scheme ..
I wouldn't get the mark by saying anything else apart from that marking point..there is no AVP in the mark schem

[007007]

Ok, well then I imagine that the larger size of axon entails a relatively lower surface area for ions to leak...?

Mark schemes are so restrictive

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[arvin_infinity]

(Original post by 007007)
Ok, well then I imagine that the larger size of axon entails a relatively lower surface area for ions to leak...?



This was posted from The Student Room's Android App on my GT-I9100

Larger size of axon gives lower SA?

Mark schemes are so restrictive

I know right..

[Hazza616]

The surface area to volume ratio would be lower i think. Thats such an obscure answer though

[Arekkusu]

Surface area is basically the answer to every single question in biology

[NinjaRikki]

(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.


+rep

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

Thats my detailed reason ))

[eggy_nog]

Is it a wjec question?


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