mýelíns

Myelins is a term that appears to be a misspelling or a less common variation of "myelin". Myelin is a fatty, insulating substance that surrounds the axons of nerve cells in the central and peripheral nervous systems. It is produced by specialized cells called glial cells: oligodendrocytes in the central nervous system and Schwann cells in the peripheral nervous system.

The primary function of myelin is to increase the speed at which electrical impulses, called action potentials, travel along the axon. It does this by forming a segmented sheath with gaps between the segments called nodes of Ranvier. The action potential "jumps" from one node of Ranvier to the next, a process known as saltatory conduction, which is significantly faster than conduction along an unmyelinated axon.

Myelin also plays a role in supporting and protecting the axons. Damage to the myelin sheath, a process called demyelination, can severely impair nerve function and lead to various neurological disorders, such as multiple sclerosis. The composition of myelin is approximately 70-80% lipid and 20-30% protein. Its white appearance is responsible for the white matter found in the brain and spinal cord.