laser A device that produces a concentrated beam of light radiation. The term is an acronym, standing for light amplification by stimulated emission of radiation. It is used in a variety of medical procedures. low-density lipoprotein (LDL) The lipid-carrying protein that transports the so-called bad cholesterol in the bloodstream. High levels of LDL cholesterol are significant risk factors in the development of atherosclerosis.
lumen The cavity or opening in tubelike organs, such as arteries.