Ultradian — rhythms are recurrent periods or cycles repeated throughout a 24 hour circadian day. (In contrast, infradian rhythms have periods longer than a day, for example the human menstrual cycle.) The descriptive term ultradian is used in sleep research… … Wikipedia
ultradian — (ˌ)əlˈtrādēən adjective Etymology: ultra + dian (as in circadian herein) : being, characterized by, or occurring in periods or cycles (as of biological activity) of considerably less than 24 hours ultradian pulses of insulin secretion an… … Useful english dictionary
ultradian — adjective Cyclical with a periodicity significantly shorter than 24 hours, that is, more frequent than circadian. Ultradian rhythms […] operate in cycles of less than 24 hours, that is they happen more than once a day … Wiktionary
ultradian — /ul tray dee euhn/, adj. of or pertaining to a biorhythm having a period of less than 24 hours. [1960 65; ULTRA + L di(es) day + AN] * * * … Universalium
ultradian — [ʌl treɪdɪən] adjective Physiology recurring more than once a day (but less than once an hour). Compare with infradian. Origin 1960s: from ultra beyond on the pattern of circadian … English new terms dictionary
ultradian — ul·tra·di·an … English syllables
ultradian — adj. denoting a biological rhythm or cycle that occurs more frequently than once in 24 hours. Compare: circadian, nyctohemeral … The new mediacal dictionary
ultradian rhythm — the regular recurrence in cycles of less than 24 hours from one stated point to another, such as certain biologic activities that occur at such intervals, regardless of conditions of illumination … Medical dictionary
Circadian — Refers to events occurring within a 24 hour period, in the span of a full (24 hour) day, as in a circadian rhythm. The word “circadian” is a 20th century invention. It was coined in 1959 from the Latin “circa” (around) + “diem” (a day). However,… … Medical dictionary
infradian — Relating to biologic variations or rhythms occurring in cycles less frequent than every 24 hours. Cf.:circadian, ultradian. [infra + L. dies, day] * * * in·fra·di·an in frā dē ən adj being, characterized by, or occurring in periods or cycles (as… … Medical dictionary
