impulse transmision...

[param124]

i have got a couple of question on the chapter nervous system...hope u guys can be able to assist me...

1) how does the electron flow from one node of ranvier to another?

2)why is the impulse transmission is one way?

..thats alll for this chapter...
thanks guys...

[sdekivit]

i have got a couple of question on the chapter nervous system...hope u guys can be able to assist me...

1) how does the electron flow from one node of ranvier to another?

2)why is the impulse transmission is one way?

..thats alll for this chapter...
thanks guys...

with nerve signalling no electrons are moved, but sodium an potassium ions are translocated over the membrane. When a node of Ranvier is present, sodiumions flow into the cell and diffuse through the nerve and cause a change in rest potential nearby. But only at the node sodiumions can again enter the nerve and diffuse.

Because the ionchannels must change to its original state, there is a period the nerve can't be stimulated, the refractory period. In this period, the nerve can't be excited. With nerve signaling through nodes of Ranvier ions flow in the nerve, but the previous node is in its refractory period and is thus not excitable and signalling goes in 1 way.