Myelin and Nervous System Functions

Dr. Donald Ozelo introduces the concept of myelin, a protective membrane that insulates axons to speed up electrical conduction. Myelin is not continuous, leaving gaps called nodes of Ranvier. In the CNS, myelin is derived from glial cells, while in the PNS, Schwann cells produce it. Myelinated fibers are known as white matter, and non-myelinated fibers are gray matter. The video recaps the importance of myelin in both the CNS and PNS.

What is the primary function of myelin in the nervous system?

• To act as an electrical insulator

• To provide nutrients to neurons

• To connect neurons together

• To store neurotransmitters

What are the gaps in the myelin sheath called?

• Synaptic clefts

• Axon terminals

• Dendritic spines

• Nodes of Ranvier

In the central nervous system, from which cells is myelin derived?

• Neurons

• Astrocytes

• Glial cells

• Schwann cells

Which cells are responsible for creating myelin in the peripheral nervous system?

• Ependymal cells

• Oligodendrocytes

• Microglia

• Schwann cells

What is the term for axons that are wrapped in myelin?

• Non-myelinated fibers

• Dendritic fibers

• Gray matter

• Myelinated fibers

What is the collective name for myelinated fibers in the central nervous system?

• Neural matter

• White matter

• Axonal matter

• Gray matter

What is the appearance of non-myelinated fibers in the central nervous system?

• Blue

• Red

• Gray

• White

Which of the following is NOT a function of myelin?

• Covering axons completely

• Providing structural support

• Acting as an electrical insulator

• Increasing conduction speed

What is the main difference between myelinated and non-myelinated fibers?

• Myelinated fibers are faster in conduction

• Non-myelinated fibers are white

• Myelinated fibers are found only in the PNS

• Non-myelinated fibers are covered by myelin