Final answer:
Orthodromic conduction is the normal direction of signal travel along an axon, while antidromic conduction is the opposite. Continuous conduction is slower and occurs in unmyelinated axons, whereas saltatory conduction is faster and occurs in myelinated axons. Axon diameter also affects conduction speed.
Step-by-step explanation:
Orthodromic conduction and antidromic conduction are terms used to describe the direction of action potential propagation along a neuron's axon. Orthodromic conduction occurs when the action potential travels from the cell body down the axon towards the axon terminal, which is the natural direction for signal propagation. In contrast, antidromic conduction happens when the action potential travels in the opposite direction, from the axon terminal towards the cell body, which is not the normal direction of travel for neuronal signals.
In terms of nerve conduction, two types of axonal conduction are continuous conduction and saltatory conduction. Continuous conduction occurs in unmyelinated axons and is characterized as slow due to the consistent opening of voltage-gated Na+ channels and the continuous influx of Na+. Saltatory conduction is present in myelinated axons and is faster because the action potential 'jumps' from node to node (node of Ranvier), effectively speeding up the transmission of the signal. Both the myelination of an axon and its diameter play a role in determining conduction speed, with wider axons offering less resistance and thus allowing for a quicker spread of depolarization.