Final answer:
Benzocaine acts as a Na* channel blocker, similar to lidocaine and novocaine, which prevents sodium from moving across nerve membranes, thereby inhibiting nerve impulses and causing temporary relief from pain and numbness.
Step-by-step explanation:
Benzocaine is a local anesthetic that functions similarly to lidocaine and novocaine by being a Na* channel blocker. This action prevents sodium from moving across the neuronal membrane, a process essential for nerve conduction. When voltage-gated sodium channels are blocked, the initiation and propagation of nerve impulses are interrupted, leading to temporary numbness and pain relief in the targeted area.
As local anesthetics, these drugs can be applied to different parts of the nervous system affecting various types of nerve fibers. When applied to the motor cortex, motor signals are inhibited, and when injected into the skin, they prevent sensory signals. A key advantage of these drugs is their reversible nature, allowing for complete recovery of nerve function without structural damage. The first local anesthetic discovered was cocaine, highlighting the historical context of these medications.