Intravenous administration of a hypotonic solution or plain distilled water will also destroy red blood cells by causing them to fill with fluid until their membranes rupture. In a transfusion reaction or in erythroblastosis fetalis, incompatibility causes the red blood cells to clump together. The agglutinated cells become trapped in the smaller vessels and eventually disintegrate, releasing hemoglobin into the plasma.
For the skate brand of the same name, see Roller Derby (brand). Roller derby is a contact sport played by two teams of five members roller skating in the same direction around a track. Game play consists of a series of short match ups (jams) in which both teams designate a jammer who scores points by lapping members of the opposing team.
Skates generally come in three basic varieties: quad roller skates, inline skates or blades and tri-skates, though some have experimented with a single-wheeled quintessence skate or other variations on the basic skate design.ost roller derby leagues adopt the rules and guidelines set by the Women's Flat Track Derby Association or its male counterpart, Men's Roller Derby Association, but there are leagues that play on a banked track, as the sport was originally from c.1933-1998.