Supporting cells of the nervous system

Question 1

What are schwann cells and describe what they do?

Answer 1

They are the PNS equivalent of oligodendrocytes (so they produce myelin sheaths around axons) but unlike in oligodendrocytes each schwann cell only envelops a short segment of one axon

==> Myelination of an entire axon requires a chain of Schwann cells

Question 2

because schwann cells only envelops a short segment of an axon it results in gaps between the segments of myelin sheath along the axon, what is the gaps between the myelin sheaths called ?

Answer 2

Nodes of ranvier

Question 3

What are capsular cells and what is their function ?

Answer 3

• Glial elements that surround the neuronal cell bodies in sensory and autonomic ganglia in the PNS
• Are flattened cells that form a nearly complete layer that separates ganglion cell bodies in DRG and some cranial nerves from surrounding non-neural connective tissue and vascular structure