1. The special action or physiologic property of an organ or other part of the body. 2. To perform its special work or office, said of an organ or other part of the body. 3. The general properties of any substance, depending on its chemical character and relation to other substances, according to which it may be grouped among acids, bases, alcohols, esters, etc. 4. A particular reactive grouping in a molecule; e.g., a functional group, such as the –OH group of an alcohol. 5. A quality, trait, or fact that is so related to another as to be dependent upon and to vary with this other. 6. A mathematical variable or expression. [L. functio, fr. fungor, pp. functus, to perform]
- allomeric f. the combined f. of the several segments of the spinal cord and medulla, communicating with each other by means of the white matter.
- arousal f. the ability of a sensory event to arouse the cortex to vigilance or readiness.
- atrial transport f. the role of the atria in filling and stretching the ventricles by their presystolic contraction, without which the force of ventricular contraction and hence the cardiac output may significantly decrease.
- discriminant f. a particular combination of continuous variable test results designed to achieve separation of groups; e.g., a single number representing a combination of weighted laboratory test results designed to discriminate between clinical classes.
- isomeric f. the individual f. of an isolated segment of the spinal cord.
- line spread f. (LSF) a measure of the ability of a system to form sharp images; in radiology, determined by measuring the spatial density distribution on film of the x-ray image of a narrow slit in a dense metal, such as uranium; from this can be calculated the modulation transfer f..
- modulation transfer f. (MTF) in testing radionuclide detectors or radiographic systems, the efficiency, at each spatial frequency, of reproducing the variation (contrast) in the object density or signal in the image; it is an expression of spatial resolution and is used to evaluate imaging systems and their components; the integral of the line spread f.; also known as the frequency response f. or contrast transmission f.; usually given as a plot of percentage amplitude response versus frequency in cycles per millimeter.

* * *

func·tion 'fəŋ(k)-shən n any of a group of related actions contributing to a larger action esp the normal and specific contribution of a bodily part to the economy of a living organism see vital function
func·tion·less -ləs adj
function vi, func·tioned; func·tion·ing -sh(ə-)niŋ to have a function <shivering \functions to maintain the heat of the body>

* * *

func·tion (funkґshən) [L. functio, from fungi to do] 1. the special, normal, or proper physiologic activity of an organ or part. 2. to perform such activity. 3. in chemistry, a characteristic behavior of a chemical compound due to the presence of a specific functional group (q.v.) 4. in mathematics, a rule that assigns to each member of one set (the domain) a value in another set (the range).

Medical dictionary. 2011.


Look at other dictionaries:

  • Function — Func tion, n. [L. functio, fr. fungi to perform, execute, akin to Skr. bhuj to enjoy, have the use of: cf. F. fonction. Cf. {Defunct}.] 1. The act of executing or performing any duty, office, or calling; performance. In the function of his public …   The Collaborative International Dictionary of English

  • Function — may refer to:* Function (biology), explaining why a feature survived selection * Function (mathematics), an abstract entity that associates an input to a corresponding output according to some rule * Function (engineering), related to the… …   Wikipedia

  • Functĭon — (v. lat. Functio), 1) Verrichtung; Amtsverrichtung; daher Functioniren, ein Amt verrichten; 2) nach Kant die Einheit der Handlung, verschiedene Vorstellungen unter eine gemeinschaftliche zu ordnen; 3) die naturgemäße Thätigkeit eines Organs; 4)… …   Pierer's Universal-Lexikon

  • Function — Func tion (f[u^][ng]k sh[u^]n), Functionate Func tion*ate, v. i. To execute or perform a function; to transact one s regular or appointed business. [1913 Webster] …   The Collaborative International Dictionary of English

  • Function — Function, lat. dtsch., Verrichtung; algebraischer Ausdruck für eine abhängige, aus andern unabhängigen Größen zu bildende veränderliche Größe; f.iren, verrichten, im Amte sein …   Herders Conversations-Lexikon

  • function — /fungk sheuhn/, n. 1. the kind of action or activity proper to a person, thing, or institution; the purpose for which something is designed or exists; role. 2. any ceremonious public or social gathering or occasion. 3. a factor related to or… …   Universalium

  • function — I. noun Etymology: Latin function , functio performance, from fungi to perform; probably akin to Sanskrit bhuṅkte he enjoys Date: 1533 1. professional or official position ; occupation 2. the action for which a person or thing is specially fitted …   New Collegiate Dictionary

  • function — Fluent Flu ent, n. 1. A current of water; a stream. [Obs.] [1913 Webster] 2. [Cf. F. fluente.] (Math.) A variable quantity, considered as increasing or diminishing; called, in the modern calculus, the {function} or {integral}. [1913 Webster] …   The Collaborative International Dictionary of English

  • function — См. funzione …   Пятиязычный словарь лингвистических терминов

  • Function word — Function words (or grammatical words) are words that have little lexical meaning or have ambiguous meaning, but instead serve to express grammatical relationships with other words within a sentence, or specify the attitude or mood of the speaker …   Wikipedia

  • Function overloading — or method overloading is a feature found in various programming languages such as Ada, C#, VB.NET, C++, D and Java that allows the creation of several methods with the same name which differ from each other in terms of the type of the input and… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.