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.
CNS: oligodendrocytes make the myelin, they cooperate in the formation of a myelin sheath along the axon, this is the process of myelination. Each oligodendrocyte produces segments of several axons. PNS: schwann cells make the myelin, each schwann cell can myelinate one segment of a single axon and they work together ot form the myelin sheath.