Dictionary

development, embryonic See prenatal development.

development The process of growth and differentiation. The most important stage of human development occurs before birth, as tissues and organs arise from differentiation of cells in the embryo. This process continues until birth, and interruptions in development result in the most serious types of birth defects, such as anencephaly and spina bifida. The developmental…

deuteranopia See colorblindness.

deuteranomaly See colorblindness.

desquamation The shedding of the outer layers of the skin. For example, when the rash of measles fades, desquamation occurs.

desquamate To shed the outer layers of the skin.

desmoplastic reaction A reaction that is associated with some tumors and is characterized by the pervasive growth of dense fibrous tissue around the tumor. The formation of scar tissue (adhesion) within the abdomen after abdominal surgery is another type of desmoplastic reaction.

desmoplasia The growth of fibrous or connective tissue anywhere in the body.

desmoid tumor, cortical A tumor that arises in embryonic tissue.

desmoid tumor A benign soft-tissue tumor that does not spread to other parts of the body. Desmoid tumors occur most often in young adults, and they usually involve the limbs or trunk, but they can also arise in the abdomen or thorax. Desmoid tumors are very difficult to remove because they adhere tenaciously to surrounding…

designer estrogen An engineered drug that possesses some, but not all, of the actions of estrogen. Also known as selective estrogen-receptor modulator (SERM). For example, raloxifene (brand name: Evista) is classified as a designer estrogen because, like estrogen, it prevents bone loss and lowers serum cholesterol; however, it does not stimulate the endometrial lining of…

designer drug A drug, typically a psychoactive drug, whose structure is a modification of a preexisting drug in order to bypass existing drug laws and regulations for the purpose of marketing. Designer drugs are dangerous, as their toxic effects and pharmacology have not been properly evaluated. They are outlawed by the US Controlled Substances Act….