What type of glial cells are specifically found in the peripheral nervous system (PNS)?

Schwann cells are the type of glial cells that are specifically found in the peripheral nervous system. These cells play a crucial role in the regeneration and repair of nerve fibers in the PNS. They are responsible for the formation of the myelin sheath around peripheral axons, which acts as an insulating layer and enhances the speed of electrical impulses along the nerve fibers.

In contrast, other glial cells mentioned have different locations and functions. Astrocytes are primarily found in the central nervous system (CNS) and are involved in supporting neurons, maintaining the blood-brain barrier, and regulating blood flow. Oligodendrocytes are also located in the CNS and have a role similar to Schwann cells but specifically myelinate axons in the central nervous system. Microglia are the resident immune cells of the CNS that respond to injury and disease. Each of these has distinct functions that do not pertain to the peripheral nervous system, highlighting why Schwann cells are unique to the PNS.