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(el′ĕ-mĕnt) [L.elementum, a rudiment] In chemistry, a pure substance consisting of only one type of atom. Further breakdown by nonchemical means of an element results in subatomic particles (protons, neutrons and electrons), which are indistinguishable from those from other elements. Elements exist in free and combined states. There are 110 named elements and others yet to be fully characterized and named. SEE: illus.





Oxygen, carbon, hydrogen, nitrogen, phosphorus, and sulfur are found in all living organisms. These six elements and calcium make up 99% of the human body mass. Sodium, potassium, magnesium, chlorine, iodine, and iron form 0.9% of the body mass.

formed e.s of blood Blood cells, as opposed to blood proteins or other chemical constituents of blood.

movable genetic e. Transposon.

rare earth e. One of a series of metallic elements that follow lanthanum (at. no. 57) in the periodic table of elements and that have oxides with similar properties. The series comprises the 14-element lanthanide series (at. nos. 58-71) and includes praseodymium, promethium, and ytterbium.

trace e. An element needed by the body in very small amounts; many are essential for enzyme functioning. Trace elements include chromium, copper, fluoride, iodine, iron, manganese, molybdenum, selenium, and zinc.


(el″ĕ-mēnt′ăl) 1. Pert. to diets that are easy to digest or are predigested. 2. Pert. to a specific element in the periodic table, e.g. calcium, iron, or phosphorus.


(ĕl″ĕ-făn-tī′ă-sĭs) [Gr. elephas, elephant + -iasis, condition] Massive swelling, esp. of the genitalia and lower extremities, resulting from obstruction of lymphatic vessels, for example by filarial parasites, malignancies, neurofibromatosis, or a familial congenital disease (Milroy disease). Prolonged swelling can cause an increase in interstitial fibrous tissue and skin puckering or breakdown. In patients with parasitic elephantiasis (the filarial diseases, common in the tropics), single-dose therapy with ivermectin or ivermectin plus albendazole destroys immature but not adult worms. SEE: lymphedema.

scrotal e. Swelling of the scrotum, usually as a result of infection of the pelvic lymphatics by filaria. SYN: chyloderma.

elephant man disease

Colloquial name for Recklinghausen's disease.

Eleutherococcus senticosus

(ĕ-loo″thĕ-rō″kok′ŭs sen″tĭ-kō′sŭs) SEE: Siberian ginseng.


(ĕl″ĕ-vā′shŭn) 1. A raised area that protrudes above the surrounding area. 2. The measured distance above a fixed object, e.g., the distance above sea level, or above a fixed anatomic structure. 3. The rise of a physiological variable above normal, e.g., in ophthalmology, the rise in intraocular pressure above what is healthy or normal; in serology, an increase in the level of ...

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