Osteocyte - Osteocyte apoptosis and associated pathologies. 1  Osteocytes die as a consequence of senescence, degeneration/necrosis, apoptosis (programmed cell death), and/or osteoclastic engulfment. [1]
Myelin is a substance which encloses the axons of neurons, providing electrical insulation that helps the nervous system function. The importance of this substance is most evident in the types of diseases that develop when it is damaged or destroyed.
The myelin sheath around most vertebrate axons provides a layer of insulation that prevents the loss of the electrical signal from an action potential. Myelin is lipid rich substance that does not conduct electricity well.ecause of the insulation provided by the myelin, action potentials can travel much more rapidly down myelinated axons than down unmyelinated axons. Myelin also isolates axons from one another in the white matter of the brain preventing the short-circuiting of nerve signals in the central nervous system.