elephant nails
elephant nails See pachyonychia congenita.
elephant nails See pachyonychia congenita.
electroshock therapy See electroconvulsive therapy.
electroretinography A test in which the electrical potentials generated by the retina of the eye are measured when the retina is stimulated by light. Abbreviated ERG. In an ERG, an electrode is placed on the cornea at the front of the eye that measures the electrical response of the rods and cones, the visual cells…
electrophoresis A method used in clinical and research laboratories for separating molecules according to their size and electrical charge. An electric current is passed through a medium that contains the mixture of molecules. Each kind of molecule travels through the medium at a different rate, depending on its electrical charge and molecular size. Separation of…
electron microscopy See electron microscope.
electron microscope A microscope in which an electron beam replaces light to form the image. An electron microscope permits greater magnification and resolution than an optical microscope, but the electron densities of objects are shown rather than their actual images. Abbreviated EM.
electromyogram A test that records the electrical activity of muscles. Normal muscles produce a typical pattern of electrical current that is usually proportional to the level of muscle activity. Diseases of muscle and/or nerves can produce abnormal electromyogram patterns. Abbreviated EMG. Also known as a myogram.
electrolyte A substance that dissociates into ions in solution and acquires the capacity to conduct electricity. Sodium, potassium, chloride, calcium, and phosphate are examples of electrolytes, informally known as lytes. Electrolyte replacement is needed when a patient has prolonged vomiting or diarrhea, and as a response to strenuous athletic activity. Commercial electrolyte solutions are available,…
electrolysis Permanent removal of body hair, including the hair root, with an electronic device. Although electrolysis is promoted as a permanent process, many people find that hair does grow back (albeit slowly) after electrolysis. Electrolysis may be done by a dermatologist, by an electrolysis technician, or by a facial technologist or esthetician.
electrolarynx A battery-operated instrument that makes a humming sound to help people who have lost their larynx talk.
electrogastrogram A test in which the electrical current generated by the muscle of the stomach is sensed and recorded in a manner very similar to that of an electrocardiogram of the heart. Abbreviated EGG. An EGG is performed by taping electrodes to the skin on the upper abdomen over the stomach. Recordings from the muscle…
electroencephalogram A technique for studying the electrical currents within the brain. Electrodes are attached to the scalp. Wires attach these electrodes to a machine, which records the electrical impulses. The results are either printed out or displayed on a computer screen. Different patterns of electrical impulses can denote various forms of epilepsy. Abbreviated EEG.