What is a myelin sheath?

Myelin is an insulating layer, or sheath that forms around nerves, including those in the brain and spinal cord. This myelin sheath allows electrical impulses to transmit quickly and efficiently along the nerve cells. If myelin is damaged, these impulses slow down. This can cause diseases such as multiple sclerosis.

What is myelin sheath?

Do Unmyelinated nerve cells have Schwann cells?

Schwann cells are a variety of glial cells that keep peripheral nerve fibres (both myelinated and unmyelinated) alive.

What are the three functions of the myelin sheath?

The myelin sheath has a number of function in the nervous system. The main functions include protecting the nerves from other electrical impulses, and speeding the time it takes for a nerve to traverse an axon.

Where is myelin sheath?

Myelin sheath is a substance which is found on neurons within the central nervous system (CNS) and the peripheral nervous system (PNS). Myelin sheath is the protective layer that wraps around the axons of neurons to aid in insulating the neurons, and to increase the number of electrical signals being transferred.

What happens without myelin sheath?

When the myelin sheath is damaged, nerves do not conduct electrical impulses normally. Sometimes the nerve fibers are also damaged. If the sheath is able to repair and regenerate itself, normal nerve function may return. However, if the sheath is severely damaged, the underlying nerve fiber can die.

Do all Schwann cells produce myelin?

Depending on the location, different glial cell types make myelin in a different manner. Schwann cells make myelin in the peripheral nervous system (PNS: nerves) and oligodendrocytes in the central nervous system (CNS: brain and spinal cord). In the PNS, one Schwann cell forms a single myelin sheath (Figure 1A).

What is the function of a Schwann cell?

Schwann cells (SCs) are the major glial cell type in the peripheral nervous system. They play essential roles in the development, maintenance, function, and regeneration of peripheral nerves. In the mature nervous system, SCs can be categorized into two major classes: myelinating and nonmyelinating cells.