myelination

myelin sheath

multilayered lipid and protein produced in neuroglia that wraps extension of plasmalemma around axons

oligodendrocytes in cns

around part of several different neuron axons

schwann cells in pns

around single neuron axon

neurolemma

aids in axon regeneration after damage

myelin sheath

inner layers wrapped around axon

nodes of ranvier

gaps in myelin sheath between cells

electrically

insulates and increases speed of nerve impulse conduction

white matter in cns presence of

myelinated axons from oligodendrocytes

white matter in cns myelin sheath

lacks neurolemma, so cns axons show little regeneration after damage

white matter in cns is

deep in brain, superficial in spinal cord

gray matter in cns

unmyelinated axons, neuron cell bodies, neuroglia

grey matter in cns is

superficial in brain, deep in spinal cord