diurnal rhythm


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di·ur·nal

(dī-ŭr'năl),
1. Pertaining to the daylight hours; opposite of nocturnal.
2. Repeating once each 24 hours, for example, a diurnal variation or a diurnal rhythm. Compare: circadian.
[L. diurnus, of the day]

diurnal rhythm

Etymology: L, diurnalis, of a day; Gk, rhythmos
patterns of activity or behavior that follow day-night cycles, such as breakfast-lunch-dinner schedules.

circadian rhythm

The diurnal cadence which, in humans (without cyclical cues provided by natural light), is 24.1–24.2 hours (older data had put this figure at 25.4 hours). Photoperiodic information from the eyes synchronises the circadian pacemaker with the light-dark cycle; circadian rhythm affects drug metabolism (e.g., antacids, halothane), serum levels of various substances (in particular adrenocortical hormones) that are routinely measured to detect and monitor disease, physiologic activities (e.g., blood pressure, myocardial blood flow and oxygen demand), psychosomatic disease and sleep cycles, cell division, haematopoiesis and natural killer cell activity.

diurnal rhythm

a pattern of activity based upon a 24-hour cycle, in which there are regular light and dark periods. See also CIRCADIAN RHYTHM.

diurnal rhythm

biological rhythm repeating cyclically throughout 24 hours
References in periodicals archive ?
Bone turnover, as assessed by several bone metabolic markers, has been reported to undergo a diurnal rhythm.
The diurnal rhythm of hOC has important implications for the selection of sampling times, e.
The biggest increase of serum FGF21 concentrations started around midnight (0000), reached its peak at around 0500 of the second day, and then slowly declined to a nadir in the afternoon, suggesting that FGF21 secretion is regulated by the diurnal rhythm in humans.
The Desa Adat community is a religio-cultural society, whose way of life is closely linked with the rites of passage and diurnal rhythms.
3 (pg/mL) Cortisol, urinary 442 69 0 to 50 ([micro]g/24h) Table 3: Comparison of laboratory studies with adrenal Cushing's syndrome and normal pregnancy Test Adrenal Normal Cushing's pregnancy syndrome Morning serum Increased Increased cortisol Diurnal rhythm Midnight Midnight of cortisol nadir lost nadir preserved Salivary Increased Increased cortisol Urinary free > 4 fold 3 fold cortisol increase increase in third trimester Low dose After test Blunted dexamethasone cortisol > 5 response suppression ([micro]g/dL) test High dose < 50% Blunted dexamethasone suppression response suppression of cortisol test Adrenocorticotropic Decreased Increased hormone (ACTH) because of placental cortisol releasing hormone (CRH)
Previous findings suggest that the transcriptional regulators upstream stimulatory factor 1 (USF1) [5] and USF2, which are related to genes involved in diurnal rhythm, are potentially significant modulators of hepcidin expression (7).
Metabolic Cycles Are Linked to the Cardiovascular Diurnal Rhythm in Rats with Essential Hypertension.
Occupational health, physiotherapy, behavioral physiology, public health, and work psychology specialists from Europe detail the health effects, risk assessment methods, interventions, and health and safety directives for work demanding high-energy metabolism, considerable muscle force, awkward postures, highly repetitive movements, high levels of mental load, and diurnal rhythm disruption, and work in heat and cold, or prolonged, low-intensity, sedentary work.
In subjects with non-suppressed cortisol levels, diurnal rhythm of cortisol was also evaluated (normal: midnight cortisol<7.
In other leafhopper and insect species, the diurnal rhythm of egg hatch likely depends on temperature, with lower temperatures causing a more equal distribution of emergence over time.