- Industry: Government
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NOAA Coral Reef Conservation Program, National Oceanic and Atmospheric Administration, U.S. Department of Commerce
A hazardous condition that scuba divers may experience at depths usually in excess of 80 ft (24.38 m). It occurs when nitrogen builds up in the body tissues and replaces some of the oxygen required by the brain. The longer a diver with conventional scuba stays at a deep depth, the more nitrogen accumulates. As the brain is deprived of oxygen, the ability to think and function clearly diminishes. It may progress from a slightly confused feeling to an almost intoxicated state, where thinking and judgement is severely impaired. If the diver does not ascend to a shallower depth and off-gas nitrogen, nitrogen narcossis may eventually cause death. Although this can happen at any depth, it is especially a problem with dives in excess of 80 feet. Nitrogen narcossis is also called 'rapture of the deep'.
Industry:Natural environment
A neurological receptor that responds to mechanical energy, e.g. Pressure, touch, and gravity.
Industry:Natural environment
A term given to the anal fin (or the anterior portion of it) of a male fish when it is modified to function as a copulatory organ, e.g., in guppies.
Industry:Natural environment
An area of high pressure. Circulation is clockwise around the high in the Northern Hemisphere and counterclockwise in the Southern Hemisphere.
Industry:Natural environment
Any epithelium having motile cilia on the free surface.
Industry:Natural environment
Describes the construction of an organism or tissue that is a mass of protoplasm which is not divided into cells, e.g., some structural parts of slime molds and fungi.
Industry:Natural environment
In genetics, the process by which offspring derive a combination of genes different from that of either parent. In higher organisms, this can occur by crossing over.
Industry:Natural environment
Molten rock that forms naturally within the Earth. Magma may be either a liquid or a fluid mixture of liquid, crystals, and dissolved gases.
Industry:Natural environment
Refers to a region of low atmospheric sea level pressure; or, the wind system around such a low pressure center that has a clockwise rotation in the Northern Hemisphere and a counterclockwise rotation in the Southern Hemisphere.
Industry:Natural environment
