Final answer:
A myelinated axon with a large diameter is typically found in motor neurons, which are responsible for transmitting signals from the CNS to muscles and glands. The myelin sheath, made up of a tightly wrapped plasma membrane of a Schwann cell, insulates the axon and speeds up the conduction of electrical impulses.
Step-by-step explanation:
A myelinated axon with a large diameter is typically found in motor neurons. Motor neurons are responsible for transmitting signals from the central nervous system (CNS) to muscles and glands, allowing them to contract or secrete. The myelin sheath, made up of tightly wrapped plasma membrane of a Schwann cell, insulates the axon and speeds up the conduction of electrical impulses.
Myelin sheaths are particularly important for long axons, as they prevent the signal from dissipating and allow for faster transmission. Examples of motor neurons with large diameter and myelinated axons include the neurons responsible for controlling voluntary movements, such as those that innervate skeletal muscles.