Answer: The myelinated nerve fibres are enveloped with Schwann cells, it form a myelin sheath around the axon.
Unmyelinated nerve fibres is enveloped by a Schwann cell that doesn't form a myelin sheath around the axon, and found in autonomous and the somatic neural systems. Sympathetic Nervous system is part of Autonomous Nervous system.
Explanation:
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Yes it is necessary for the production of apt in your cells because apt needs oxygen to form correctly.
Is when you breathe in oxygen and exhale carbon dioxide
Factories, cars and cigoretes.
All of these things are polluting the air cuasing it to heat up more which is cuasing global warming