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(kom′pĕt-ĕns) [L. competere, to meet, agree] 1. In psychiatry and in law, ability to manage one's affairs, and by inference, that one is sane; mental competence. 2. Performance in a manner that satisfies the demands of a situation; effective interaction with the environment.

competency validation program

Core competency.


(kŏm″pĕ-tĭsh′ŭn) The simultaneous attempt of similar substances to attach to a receptor site of a cell membrane.


(kŏm-plānt′) 1. The principal reason for seeking medical assistance. 2. The initial pleading or document that commences a legal action, states grounds for such an action, names the parties to the lawsuit, and demands for relief. SYN: petition.

chief c. ABBR: CC. The symptom or group of symptoms that represents the primary reason for seeking health care.

subjective memory c. Subjective memory impairment.


(kom′plĕ-mĕnt) [L. complere, to complete] A group of proteins in the blood that play a vital role in the body's immune defenses through a cascade of interactions. Components of complement are labeled C1 through C9. Complement acts by directly lysing (killing) organisms; by opsonizing an antigen, thus stimulating phagocytosis; and by stimulating inflammation and the B-cell-mediated immune response. All complement proteins lie inactive in the blood until activated by either the classic or the alternative pathways.

The lack of any of the more than 25 proteins involved in the complement system may affect the body's defenses adversely. Lack of C3, for example, increases susceptibility to common bacterial infections, and deficiencies in C5, C6, C7, and C8 increase susceptibility to invasive meningococcal disease, including meningococcal meningitis. Deficits of C5, C6, C7, C8, and C9 (the terminal components of complement) are often associated with autoimmune diseases, such as systemic lupus erythematosis and glomerulonephritis. Lack of C1 causes hereditary angioedema of the extremities and the gastrointestinal tract.


(kom″plĭ-ment′ă-rē, kom″plĭ-men′trē) 1. Supplying something that is lacking in another system or entity. 2. Having an inverse relationship with another molecule so that the two molecules attract or bind to each other perfectly. 3. Being a reversed copy of another molecule, e.g., complementary DNA. 4. In mathematics, any two angles that sum to 90°.

complementation group

(kom″plĕ-mēn-tā′shōn) A subtype of a genetic illness; e.g., Fanconi anemia has 15 different complementation groups, each with its own signs and symptoms.

complement-fixation reaction

A reaction seen when complement enters into combinations formed between soluble or particulate antigens and antibody. It is used to diagnose many infectious illnesses, including chlamydia, syphilis, and mycoplasma, among others. SEE: complement; complement fixation.

complement unit

The smallest ...

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