How is nocturia, frequent need to urinate, particular to nighttime, possible? How does time of day influence this need to urinate, or might this be an illusion?
I'm not nearly qualified to give you a definite answer, but my guess is, that it doesn't have to do with the time of day at all, but rather with your sleep patterns. The part of the nervous system which deals with stuff you can't control, like bowel movements, and urineproductioncontrol, pupil-dilation, heart-rate and so on, is called the autonomic nervous system. When you sleep, or relax, it enhances functions such as digestion. When your frightened, (let's say you're robbed) your heart-rate goes up, trachea is dilated, pupils dilate, but your digestion and urine-produciton goes down (to name a few functions).How does time of day influence this need to urinate, or might this be an illusion?
Circadian rythms are proven to be endogenous, merely affected by melatonin release. Experiments in the 19th century proved that primates, locked in a room with non-variable light strength, kept circadian rythms.Our bodies have circadian rhythms, synchronized by melatonin release (melatonin is released at night and lower when we're exposed to light), of all sorts of functions...
Actually, the definition of a circadian rhythm requires it to be endogenous, it is not something "proven" but required. "Merely affected" is rather downplaying the role of melatonin for entraining the rhythms, although in the absence of photoperiodic cues, melatonin also has endogenous patterns of release. Not quite sure what point you were trying to make though.Circadian rythms are proven to be endogenous, merely affected by melatonin release. Experiments in the 19th century proved that primates, locked in a room with non-variable light strength, kept circadian rythms.
No, that's a diurnal rhythm, which can be endogenous or driven by external cues. A circadian rhythm is endogenous, by definition. I know, the general biology textbooks never make this distinction between definitions of diurnal and circadian rhythms clear and leave a lot of students confused on this point, so that's probably where your confusion is coming from too.Circadian rythm = any rythmic behaviour with periodic time of 24 hours