Question

1. what is an insulating layer around some axons in the brain and what is it made of?

myelin; schwann cells
astrogila; schwann cells
oqlioglia; neurons

Explanation:

Myelin is the insulating layer around axons. In the peripheral nervous system (which includes parts related to the brain's connections), Schwann cells produce myelin. Astroglia (astrocytes) have other functions like supporting neurons. Oligoglia (oligodendrocytes) produce myelin in the central nervous system (not Schwann cells for that part). Neurons are not what make the insulating layer. So the correct answer is myelin made by Schwann cells.

Answer:

myelin; Schwann cells