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.
Schwann cells: these cells provide the myelin that covers neurons in the peripheral nervous system. Larger neurons are covered in a myelin sheath. Myelin is high in lipid and serves the same purpose as insulation around electrical wires.Myelinated axons conduct nerve impulses faster.hese cells form the substance of the brain, spinal cord, and peripheral nervous system. The brain is composed of the basic units of the cerebral hemispheres, brainstem, and cerebellum. The cerebral hemispheres can be further categorized by structure and function.