biological rhythm

any periodic variation in a living organism’s physiological or psychological function, such as energy level, sexual desire, or menstruation. Such rhythms can be linked to cyclical changes in environmental cues, such as daylength or passing of the seasons, and tend to be daily (see circadian rhythm) or annual (see circannual rhythm). They also can vary with individuals and with the period of the individual’s life. Also called biorhythm; endogenous rhythm; internal rhythm; life rhythm. See also infradian rhythm; ultradian rhythm.

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Psychology term of the day

December 24th 2024

dihydroergotamine

n. a semisynthetic derivative of the ergot alkaloid ergotamine, used in the treatment of acute migraine headache. It is a potent vasoconstrictor due to its ability to antagonize alpha-adrenergic receptors in blood-vessel walls as well as serotonin and dopamine receptors. U.S. trade names: DHE 45; Migranal.