Single function switches are the most commonly used adaptive switches. This type of switch performs one function (i.e., on/off) this switch has only one function - on or off. The switch may only be in one of the states at any one moment in time. Multiple function switches may perform two or more functions.
Echinocytes and keratocytes should be considered in the differential diagnosis of spur cell anemia. Echinocytes or burr cells are spiculated red blood cells with uniform, narrow, spikelike surface projections. Spur cells have fewer spicules, and the spicules vary more in size than echinocytes. Keratocytes are acanthocytelike cells with bizarre shapes and horny projections. Differential Diagnoses.
Natural killer cell: A cell that can react against and destroy another cell without prior sensitization to it. Abbreviated NK cell. NK cells are part of our first line of defense against cancer cells and virus-infected cells. NK cells are small lymphocytes that originate in the bone marrow and develop without the influence of the thymus. An NK cell attaches to a target cell, releases chemicals that breach its cell wall, and causes it to lyse (break up).