META

META (Greek - "together with something," as well as "after something," "afterwards"), an extremely common prefix to various terms of biological, chemical, and pathological character. The addition of the prefix meta to the basic term changes the meaning of the latter. This change of meaning is however not always unambiguous and to a large extent depends on the content of the basic term, and in some cases there is simply a conventional "27 condition. Most often the prefix meta is used to indicate the emergence of qualitatively new phenomena occurring in connection with the basic process and precisely after it, e.g., metapneumonic empyema (empyema following pneumonia), meta-syphilitic affections of the nervous system (tabes dorsalis, progressive paralysis), meta-phase (in karyokinesis), metaplasia, metamorphosis, metabolism, metastasis, metamyelocyte, etc. In all these cases, therefore, we are dealing with dynamic phenomena, and meta-processes indicate one of the sequential stages in the chain of these phenomena. Meta-processes closely border on processes denoted by terms with the prefix ana- and cata-, and sometimes include them within themselves; e.g., ana- and catabolism can be considered as two aspects of metabolism, anaplasia-as a special case of metaplasia. The prefix meta is also used for purely topographical distinctions, to indicate the existence of two objects or phenomena that are not genetically related to each other and are therefore essentially static, e.g., metatarsal, metacarpal bones (metatarsalia, metacarpalia), metaphysis. Here the prefix meta takes on the value of the prefix para- (abbr.). In biology, chemistry with the help of the prefix meta, a conventional distinction is often made between species and varieties of the animal world, different oxides, stereoisomers (meta-zoa, Metastrongylus, Metaphyta; meta-compounds in chemistry, e.g., metaphosphoric acid, meta-albumin). In all these cases, the prefix meta above all has a classificatory value, often being contrasted with other prefixes (ortho, para).