15.4 Speed Of The Nerve Impulse Flashcards
1
Q
Explain the effect of myelination on the rate of nerve impulse conduction
A
- Myelin prevents ion movement
- nerve impulse undergo saltatory conduction
2
Q
What does a larger diameter of the axon have on the speed of conductance?
A
- faster speed of conductance
- less leakage of ions
3
Q
What is the all or nothing principle?
A
- above threshold-> action potential
- below threshold level -> no action potential
4
Q
What happens to the action potentials if there is a large stimulus intensity?
A
Increase in frequency of action potentials
5
Q
Draw the graph illustrating neurone excitability before and after a nerve impulse
A
Page 358
6
Q
What are the 3 purposes of a refractory period?
A
- unidirectionality
- discrete impulses
- limits number of action potentials
7
Q
Why is there less leakage of ions if the axon diameter is larger?
A
Smaller surface area to volume ratio
