Glia and Myelination

neuroglia

supporting cells of the nervous system that are intimately related to neurons and their processes

neuroglia

some types are involved in excitation, inhibition or propagation of the nerve impulse

astrocytes, oligodenroglia, microglia

What are the 3 NCS types of neuroglia?

Schwann cells

What are the PNS neuroglia called?

astrocytes

forms structural support of the CNS, removes debris, helps form the blood-brain barrier, nourishes neurons, releases calcium which can increase or decrease communication between neurons

microglia

CNS neuroglia that are similar to macrophages in that they are phagocytic (break down and dispose of any damaged cells)

myelin

a substance of proteins and fats that surround an axon, insulating it and supporting the flow of the action potential.

Nodes of Ranvier

gaps in the myelin where sodium channels can open and continuously generate more action potentials

myelination

Disruption of ________ at a young age can cause developmental delays because it can cause problems with nerve conduction.

CNS - Oligodendroglia

PNS - Schwann cells

What are the two types of myelin? (CNS and PNS)

produce and maintain the myelin sheaths in the CNS and PNS

What do both types of myelin do?

• occurs when the immune system mistakenly goes after your (schwann) cells

• occurs 2-3 weeks after a mild infection (most of the time intestinal)

• presents like a neurological event (ex. cannot walk)

Explain what Guillain-Barré is? (demyelinating disorder in the PNS)

Oligodendrocytes in the brain or spinal cord produce areas of demyelination, called plaques.

• These plaques cause the action potentials to not be able to continuously depolarize like usual.

Explain Multiple Sclerosis (MS) (demyelinating disorder in the CNS)

MS

autoimmune, chronic disorder, typically beginning in adulthood that involves dysfunction of (commonly) vision, sensation, clumsiness, loss of balance, and brain fog

MS

demyelinating disorder that may involve the cranial nerves

the myelin project

a nonprofit medical research and advocacy organization founded in 1989 by Augusto and Michaela Odone after their son Lorenzo was diagnosed with adrenoleukodystrophy (ALD), a rare disease that destroys the myelin sheath around nerve fibers

• Hereditary neurodegenerative disorders