A mixed tideâtwo uneven tides a day, or one high and one lowâis also possible. Tides vary on timescales ranging from hours to years due to a number of factors. To make accurate records, tide gauges at fixed stations measure water level over time.
Top 10 facts about the world. Oligodendrocytes, also known as oligodendroglia, are a type of brain cell in the central nervous system that belongs to the glial cell family. The main purpose of glial cells is maintenance and support of nervous system cells.
Schwann cells are the cellular counterparts to oligodendrocytes in the peripheral nervous system. Similarly to oligodendrocytes they form the myelin sheath. In contrast to the oligodendrocyte each Schwann cell is associated with only one axonal segment.he major function of oligodendrocytes and Schwann cells is the formation of myelin. Myelin acts as an insulator of axonal segments and is a prerequisite for the high velocity of nerve conduction, of up to 200 m/second.