- distribution
**1.**The*passage*of the branches of arteries or nerves to the tissues and organs.**2.**The*area*in which the branches of an*artery*or a*nerve*terminate, or the*area*supplied by such an*artery*or*nerve*.**3.**The relative numbers of individuals in each of various categories or populations such as in different age, sex, or occupational samples. See*frequency*d..**4.**Partition.**5.**The*pattern*of occurrence of a*substance*within or between cells, tissues, organisms, or*taxa*. [L. distribuo, pp. -tributus, to distribute, fr. tribus, a*tribe*]-the*Bernoulli*d.*probability*d. associated with two mutually exclusive and exhaustive outcomes, e.g.,*death*or*survival*.-*binomial*d.**1.**a*probability*d. associated with two mutually exclusive outcomes, e.g., presence or*absence*of a*clinical**sign*.**2.**the possible array of the*number*of successes in the outcomes from a fixed*number*,*n*, of independent*Bernoulli trial*s; the probabilities associated with each constitute a*binomial**process*of*order**n*.-**chi-square d.**(ki) a*variable*is said to have a*chi-square*d. with*K*degrees of freedom if it is distributed like the sum of the squares of*K*independent*random*variables, each of which has a*normal*(*gaussian*) d. with*mean**zero*and*variance*one. The chi square d. is the*basis*for many variations of the chi-square(d)*test*, perhaps the most widely used*test*for*statistical significance*in*biology*and*medicine*.-a*countercurrent*d.*method*of*separation*of two or more substances by repeated d. between two*immiscible**liquid*phases that move past each other in opposite directions; a*form*of liquid-liquid*chromatography*.-**dermatomal d.**SYN:*dermatome*(3).-**epidemiological d.***histogram*.-**f d.**the d. of the*ratio*of two independent quantities each of which is distributed like a*variance*in normally distributed samples. So named in honor of the English statistician and*geneticist*R.A.*Fisher*.-a statistical description of raw*frequency*d.*data*in terms of the*number*or*frequency*of items characterized by each of a*series*or*range*of values of a continuous*variable*.-**lognormal d.**if a*variable*y is such that x = log y, it is said to have a lognormal d.; this is a*skew*d..-**multinomial d.***probability*d. associated with the*classification*of each of a*sample*of individuals into one of several mutually exclusive and exhaustive categories.-a*normal*d.*specific*bell-shaped*frequency*d. commonly assumed by statisticians to represent the infinite*population*of measurements from which a*sample*has been drawn; characterized by two parameters, the*mean*(x) and the*standard**deviation*(σ), in the*equation*: SYN:*gaussian*curve,*gaussian*d..-*Poisson*d.**1.**a discontinuous d. important in statistical*work*and defined by the*equation*p (x) = e^{-μ}μ^{x}/ x!, where e is the*base*of natural logarithms, x is the*sequence*of integers,*μ*is the*mean*, and x! represents the*factorial*of x.**2.**a d.*function*used to describe the occurrence of rare events, or the*sampling*d. of isolated counts in a continuum of*time*or*space*.-the d. of the*t*d.*quotient*of independent*random*variables, the numerator of which is a standardized*normal**variate*and the*denominator*the*positive*square*root*of the*quotient*of a*chi-square*distributed*variate*and its*number*of degrees of freedom.* * *

**dis·tri·bu·tion .dis-trə-'byü-shən***n*the pattern of branching and termination of a ramifying anatomical structure (as a nerve or artery)* * *

dis·tri·bu·tion (dis″trĭ-buґshən) [L.*distributio*] 1. the specific location or arrangement of continuing or successive objects or events in space or time. 2. the extent of a ramifying structure such as an artery or nerve and its branches. 3. the geographical range of an organism or disease. 4. probability d. 5. in statistics, a synonym for*law;*for entries not found here, see under*law.*

*Medical dictionary.
2011.*