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.
How Big is a Roller Derby Track? The roller derby track is almost oval shaped. Its inside line is a perfect oval, 25 feet (7.6m) across and 60 feet (18.3m) long. The track itself varies between 13 and 15 feet (4 -4.6m) wide so the outside line of the oval is an irregular shape.