Schwann Cells Definition
Schwann cells are glial cells that surround neurons, keeping them alive and coating them with a myelin sheath in certain cases. The peripheral nervous system contains Schwann cells, but the central nervous system has oligodendrocytes, which are related cells. These cells surround nerves to keep them in place, provide nourishment and oxygen to neurons, insulate neural pathways, and prevent neurons from being infected.
Schwann Cells Overview
Nerves work by sending electrical impulses across their cell membrane. The signal goes to the nerve cell’s terminal, where it is chemically transferred to the next nerve cell. This requires a lot of energy and a unique structural pattern, rendering nerve cells incapable of self-care.
Schwann cells (and other glial cells) have a role in this. A glial cell is similar to a caregiver for a nerve cell. Glial cells come in a variety of shapes and sizes, depending on which area of the nervous system you’re looking at. Schwann cells are found in the peripheral nervous system, which includes all nerve cells outside the brain and spinal cord. Schwann cells provide many of the duties that nerve cells are unable to fulfil.
Schwann Cell Function
When it comes to maintaining nerves, Schwann cells have four primary responsibilities. They must first support the nerve’s physical placement and safeguard it from external injury. As a result, the majority of Schwann cells are found wrapped around the nerves they protect. A nerve cell is usually surrounded and encapsulated by a large number of these tiny cells. These cells develop connections with the extracellular matrix and other cells in the surrounding area, securing the nerve cell in place and allowing it to make the connections it needs.
Second, Schwann cells must provide oxygen and nutrients to the underlying nerve cells, partially because nerve cells are busy delivering neurological signals and partly because they are surrounded by glial cells. As a result, these cells have unique membrane properties that enable nutrients and oxygen to move freely into the nerve cell.
Though not all Schwann cells form a myelin sheath, these glial cells play an important role in insulation. They physically isolate a neuron from touching other nerves as they wrap themselves around it, giving it the third function of insulation. Myelinated nerve cells are those that have had their myelin sheaths removed. The myelin sheath is made by Schwann cells.
Myelin is a non-conductive fatty material generated by glial cells. Myelinating a nerve cell guarantees that the signal is insulated, similar to how cables with insulation lose less current. Myelinated nerve cells have been found in experiments to transport impulses up to 10 times more quickly than unsheathed nerves.
That is one of the reasons why Multiple Sclerosis (MS) may be so debilitating. As Schwann cells die, a patient with MS gradually loses myelin sheaths. This results in random nerve signals, slower nerve signal transmissions, and the possibility of nerve injury. This results in the loss of nervous system function, which may cause symptoms such as numbness, blindness, and death.
That is one of the reasons why Multiple Sclerosis (MS) may be so debilitating. As Schwann cells die, a patient with MS gradually loses myelin sheaths. This results in random nerve signals, slower nerve signal transmissions, and the possibility of nerve injury. This results in the loss of nervous system function, which may cause symptoms such as numbness, blindness, and death.
Schwann Cells vs Oligodendrocytes
Schwann cells resemble oligodendrocytes, which are present in the central nervous system. There is, however, one significant distinction. Oligodendrocytes attach to a variety of nerve cells and produce myelin sheaths surrounding them. Schwann cells, on the other hand, surround just one nerve cell, and there are often several Schwann cells surrounding a single nerve cell
This distinction is mostly due to the structural and functional differences between nerve cells in the central and peripheral nervous systems. Nerve cells in the central nervous system are densely packed and must maintain close contact with one another. As a result, a single oligodendrocyte may quickly reach and protect a variety of neurons while also holding them in place. Nerves, on the other hand, are few in the peripheral nervous system. Many Schwann cells may surround these very long nerve cells, assisting in signal transmission to the furthest reaches of the body!
