dilation, pupil 1 A type of eye examination that enables an eye-care professional to see more of the retina, the light-sensitive layer of tissue at the back of the eye. Dilating the pupil permits the retina to be examined for signs of disease. To dilate the pupil, drops are placed into the eye. 2 A…
dilation See dilatation.
dilating The widening and opening of an opening, such as the cervix or esophagus. For example, the amount of widening can be described in terms of the number of fingers that could fit in the cervical opening, or it is described in centimeters.
dilate To stretch or enlarge. Also known as dilatate.
dilatation The process of enlargement or expansion. Also known as dilation.
dilatate In medicine, to enlarge or expand. Also known as dilate.
digitalis A chemical from the dried leaf of the common foxglove (Digitalis purpurea) plant that is to used to strengthen the force of the heartbeat. The Scottish physician William Withering discovered this use for digitalis in the late 1700s. Digitalis, its components, and their derivatives have long been used to treat congestive heart failure and…
digital rectal exam A routine exam in which a physician inserts a lubricated, gloved finger into the rectum and feels for abnormal areas to detect rectal cancer and, in a man, inflammation, enlargement, or cancer of the prostate as well as nerve problems indicated by reduction of the normal tone of the muscles of the…
digit, supernumerary An extra finger or toe.
digit A finger or toe.
digestive system The system of organs responsible for getting food into and out of the body and for making use of food to keep the body healthy. The digestive system includes the salivary glands, mouth, esophagus, stomach, liver, gallbladder, pancreas, small intestine, colon, and rectum. The digestive system’s organs are joined in a long, twisting…
DiGeorge syndrome A congenital disorder characterized by low blood calcium because of underdevelopment of the parathyroid glands needed to control calcium; immunodeficiency due to hypoplasia of the thymus (an organ behind the breastbone in which lymphocytes mature and multiply); and defects involving the outflow tracts from the heart. DiGeorge syndrome is caused by a very…