3. Sea vegetables. Sea vegetables are rich in iodine. Iodine attaches to tyrosine (an amino acid) to form thyroxine. If you have insufficient levels of iodine, it becomes a rate-limiting step in the production of thyroid hormones and you'll inhibit your thyroid function.
Confidence votes 48. Special glia called Schwann cells form the myelin sheath which cover axons in the peripheral nervous system. The myelin sheath is actually two layers. The first layer surrounding the axon is called the myelin sheath and it is made up of the plasma membrane of the Schwann cells. The Schwann cells cytoplasm creates the second layer and is called the neurolemma. A neuron in the peripheral nervous system with a myelin sheath is called a myelinated neuron.
The myelin sheath is a protective covering that surrounds fibres called axons, the long thin projections that extend from the main body of a nerve cell or neuron.This sheath is composed of protein and lipids.he main function of myelin is to protect and insulate these axons and enhance their transmission of electrical impulses. If myelin is damaged, the transmission of these impulses is slowed down, which is seen in severe neurological conditions such as multiple sclerosis.