Medullary Sheath (Noun)
Meaning
A layer of myelin encasing (and insulating) the axons of medullated nerve fibers.
Classification
Nouns denoting body parts.
Examples
- The medullary sheath is composed of lipids and proteins that provide electrical insulation to the axon, facilitating the transmission of nerve impulses.
- In the central nervous system, the medullary sheath is formed by oligodendrocytes, which wrap layers of myelin around the axons of multiple neurons.
- The medullary sheath is interrupted at regular intervals by gaps called nodes of Ranvier, where the axon is exposed to the surrounding tissue.
- Damage to the medullary sheath can lead to demyelinating diseases such as multiple sclerosis, which disrupts nerve function and causes a range of neurological symptoms.
- The thickness and composition of the medullary sheath can vary depending on the type of nerve fiber and its location in the body.