(1) Nervous System - Glial Cells

in PNS

more numerous than neurons

Where are glial cells located?

Satellite Cells

surround neuron cell bodies in spinal ganglia

PNS

What is this?

which nervous system is this apart of?

protect the cell body

nutrient exchange and waste removal

What do Satellite cells do?

group of neuron cell bodies located outside the CNS

swelling

what are Ganglions?

Neurolemmocytes (Schwann cells)

myelinate axons in PNS

What is this?

protect axon

insulate axon to produce faster nerve impulse

regenerate damaged PNS axons

What do myelin do?

Astrocytes

in CNS

What cell is this?

which nervous system is it apart of?

regulate transfer of materials from blood to brain

make vessels less “leaky”

What do astrocytes do?

keeps harmful substances away from brain

What is the purpose of the Blood Brain Barrier?

dopamine can’t pass through the BBB

Why can’t you give chemotherapy for brain cancer?

oligodendrocytes (few branches cells)

myelinate axons in CNS

What cell is this?

what does it do?

Microglia

replicates and phagocytize damaged neurons in the CNS

What cell is this?

Ependymal Cells

line central canal and ventricles

help circulate cerebrospinal fluid (CSF)

What cell is this?

spaces within the brain

CSF produced here

What are ventricles in a neuron?

space with spinal cord

What is the central canal in the neuron?

wrapping an axon with myelin

insulates axon and produces faster nerve impulse

What is myelination?

neurolemmocyte wraps around 1 mm portion of an axon

cytoplasm and nucleus are squeezed to the outside

Myelination procedure in PNS

neurofibril nodes

nerve impulse is generated in this gap

what are neurolemmocytes separated by?

one oligodendrocyte myelinates 1 mm portions of many axon

Myelination procedure in CNS

nerve impulse must spread along entire length

Why do unmyelinated axons take longer to produce nerve impulses?

nerve impulse jumps from node to node

Why do myelinated axons produce faster impulses than unmyelinated axons?