4. What is the function of a Schwann cell, and where is it found?

Schwann cells are a type of glial cell in the peripheral nervous system (PNS). Their primary functions include: 1. **Myelination**: Schwann cells wrap around the axons of neurons to form the myelin sheath, which insulates the axon and increases the speed of electrical signal transmission along the nerve fibers. 2. **Support and Repair**: They provide structural support to neurons and play a crucial role in the repair and regeneration of damaged nerve fibers in the PNS. 3. **Nutritional Support**: Schwann cells also supply nutrients to the neurons and help maintain the overall health of the nerve fibers. In summary, Schwann cells are found in the peripheral nervous system, where they are essential for the myelination of axons and the support and repair of nerve cells.