Final answer:
The myelin-forming glia in the PNS is the Schwann cell, which insulates individual axon segments with myelin to enhance signal conduction.
Step-by-step explanation:
The myelin-forming glia in the Peripheral Nervous System (PNS) is the Schwann cell. Schwann cells are dedicated to insulating a single axon segment with myelin in the PNS. This differs from the oligodendrocyte, which is another type of glial cell found in the Central Nervous System (CNS) that insulates axons with myelin. Oligodendrocytes can extend their processes to insulate multiple axon segments, whereas each Schwann cell insulates just one axon segment. The primary function of the myelin sheath, produced by both Schwann cells and oligodendrocytes, is to enhance the speed and efficiency of electrical signal conduction along the nerve cell axon.