Chapter 3: Myelin Sheath Flashcards
1
Q
What are Myelin Sheaths?
A
Sleeves of fatty substance that wrap around and insulate nerve fibers (axons) like insulation around electrical wires.
2
Q
Where are Myelin Sheaths found?
A
In the brain and spinal cord.
3
Q
What is the 2nd function of Myelin Sheaths?
A
Increase the speed of electrical communication between neurons.
4
Q
Myelin Sheaths cover most of the nerve fiber but where does it has gaps?
A
At regular intervals along the axon.
5
Q
What can cross the axon only at these Myelin Gaps?
A
Particles called ions.
6
Q
What are the Nodes of Ranvier?
A
The Myelin gaps.
7
Q
What does the Nodes of Ranvier do?
A
Helps maintain the electrical signal allowing it to travel quickly down an axon.
8
Q
The loss of Myelin results in what?
A
In CNS disorders, most notably, multiple sclerosis.
