Final answer:
A large diameter axon has a faster conduction velocity compared to a small diameter axon due to reduced internal resistance, with myelinated axons featuring even quicker conduction due to saltatory conduction 'leaping' between nodes of Ranvier.
Step-by-step explanation:
When comparing the conduction velocity of a large diameter axon versus a small diameter axon, it's important to consider that a large diameter axon will generally have a faster conduction speed. This is due to the fact that the larger diameter reduces the internal resistance to the current flow. In the context of nerve cells, or neurons, a larger diameter allows for a quicker depolarization spread.
Additionally, the type of conduction also plays a role. Continuous conduction occurs in unmyelinated axons and is slower because it involves a consistent opening of voltage-gated Na+ channels and an influx of Na+ ions across the entire axonal membrane. On the other hand, saltatory conduction takes place in myelinated axons and is much quicker, as the action potential effectively 'leaps' from one node of Ranvier to the next, with fewer points where Na+ enters the cell.
Therefore, with all else being equal, a larger diameter axon will conduct signals faster than a smaller one, and if the axon is also myelinated, the conduction will be even faster compared to an unmyelinated axon of the same size.