Schwann Cells

Definition

Schwann cells are a type of glial cell found in the peripheral nervous system. They are responsible for forming the myelin sheath around the axons of neurons, which is crucial for the efficient transmission of electrical signals throughout the body.

5 Must Know Facts For Your Next Test

1. Schwann cells produce a fatty substance called myelin, which wraps around the axons of neurons in the peripheral nervous system.
2. The myelin sheath acts as an insulator, increasing the speed of electrical signal transmission along the axon through a process called saltatory conduction.
3. Schwann cells also play a crucial role in the regeneration of damaged peripheral nerves by providing a supportive environment for axon regrowth.
4. In the central nervous system, the myelin sheath is produced by a different type of glial cell called oligodendrocytes.
5. Disorders affecting the Schwann cells, such as Charcot-Marie-Tooth disease, can lead to impaired nerve function and peripheral neuropathy.

Review Questions

• Explain the role of Schwann cells in the peripheral nervous system.
  • Schwann cells are a crucial component of the peripheral nervous system. They are responsible for forming the myelin sheath around the axons of neurons, which acts as an insulator and greatly increases the speed of electrical signal transmission. The myelin sheath is produced by Schwann cells wrapping their plasma membrane multiple times around the axon, creating a segmented structure that allows for faster, more efficient propagation of action potentials through a process called saltatory conduction. Schwann cells also play a vital role in the regeneration of damaged peripheral nerves, providing a supportive environment for axon regrowth.
• Describe the differences between Schwann cells and oligodendrocytes in terms of myelination.
  • While both Schwann cells and oligodendrocytes are responsible for producing the myelin sheath, they differ in their location and the specific neurons they myelinate. Schwann cells are found in the peripheral nervous system and myelinate the axons of peripheral neurons, whereas oligodendrocytes are found in the central nervous system and myelinate the axons of central neurons. Additionally, Schwann cells wrap their plasma membrane multiple times around a single axon, while oligodendrocytes extend processes that myelinate multiple axons simultaneously. This difference in myelination patterns contributes to the distinct functions and properties of the central and peripheral nervous systems.
• Analyze the implications of Schwann cell dysfunction and its potential impact on nervous system function.
  • Disorders that affect the proper functioning of Schwann cells can have significant consequences for the peripheral nervous system. For example, in Charcot-Marie-Tooth disease, a genetic disorder that disrupts Schwann cell development and myelination, the resulting impairment of nerve function can lead to progressive muscle weakness, sensory loss, and mobility issues. The inability of Schwann cells to form a healthy myelin sheath around peripheral neurons compromises the speed and efficiency of electrical signal transmission, leading to various neurological symptoms. Additionally, the reduced capacity of Schwann cells to support nerve regeneration in the event of injury or damage can further exacerbate the impact on overall nervous system function. Understanding the critical role of Schwann cells in maintaining the integrity and functionality of the peripheral nervous system is essential for developing effective treatments for disorders related to Schwann cell dysfunction.

Related terms

Myelination: The process by which Schwann cells wrap their plasma membrane multiple times around the axon of a neuron, forming the myelin sheath.

Peripheral Nervous System (PNS): The part of the nervous system that includes all the nerves outside the central nervous system (brain and spinal cord).

Axon: The long, slender projection of a neuron that transmits electrical signals away from the cell body to other neurons or target cells.