Myelin insulates peripheral nerve axons. What is unusual about its membrane composition?

1. Myelin is an outgrowth of the membrane of specialized cells that insulates the axons of the peripheral nerves. 2. It contains only 18 percent protein and 76 percent lipid, so it is unusually lipid rich. 3. The inverse figures, 76 percent protein and 24 percent lipid, belong to the mitochondrial inner membrane, which is the trap here. 4. Fifty percent protein with 40 percent lipid is the typical human cell figure, not myelin. 5. Thirty percent lipid is the figure quoted for the plasma membrane of human red blood cells. 6. An insulating sheath sits at the lipid rich end of the range, which fits 18 percent protein. _Source: OpenStax Biology (1st ed., CC BY 4.0), Ch 5 "Structure and Function of Plasma Membranes", section 5.1 Components and Structure_