have voltage-reg. gates along the entire axolemma
when APs occur at the trigger zone:
Na+ enters and diffuses to adjacent areas
opening voltage gates just distal to the AP
Na+ and K+ gates open and close as at the trigger zone
this excites the membrane just distally
chain reaction travels to the end of the axon
relatively slow in unmyelinated axons
voltage-reg. gates are scarce in the internodes
400 times more at the nodes
Na+ cant diffuse anyway due to myelin sheath
so the APs jump from node to node:
transmit the signal much faster
Please allow access to your computer’s microphone to use Voice Recording.
We can’t access your microphone!
Click the icon above to update your browser permissions and try again
Reload the page to try again!
Press Cmd-0 to reset your zoom
Press Ctrl-0 to reset your zoom
It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.
Your microphone is muted
For help fixing this issue, see this FAQ.