An investigation was carried out to study the speed of nerve impulse propagation (conduction velocity) in both myelinated and unmyelinated neurones at various ambient temperatures.
The table shows the results of this investigation:
| Temperature in ∘C^\circ\text{C}∘C | Conduction velocity in unmyelinated neurone in m s−1\text{m s}^{-1}m s−1 | Conduction velocity in myelinated neurone in m s−1\text{m s}^{-1}m s−1 |
|---|---|---|
| 5.0 | 0.4 | 12.0 |
| 10.0 | 0.8 | 25.0 |
| 15.0 | 1.1 | 42.0 |
| 20.0 | 1.1 | 65.0 |
| 25.0 | 1.5 | 92.0 |
| 30.0 | 2.1 | 125.0 |
Suggest why the investigation was carried out using neurones with the same axon diameter.
Compare the effect of increasing temperature on conduction velocity in the unmyelinated neurone and in the myelinated neurone.
Suggest why conduction velocity increases with temperature and is significantly higher in the myelinated neurone compared to the unmyelinated neurone.
Suggest a laboratory method that could be used to measure the conduction velocity of an action potential along an isolated neurone.
