A circadian rhythm (/sərˈkeɪdiən/), or circadian cycle, is a natural oscillation that repeats roughly every 24 hours. Circadian rhythms can refer to any...

Circadian rhythm sleep disorders (CRSD), also known as circadian rhythm sleep-wake disorders (CRSWD), are a family of sleep disorders which affect the...

Light effects on circadian rhythm are the response of circadian rhythms to light. Most animals and other organisms have a biological clock that synchronizes...

environment, primarily daylight and darkness. Circadian clocks are the central mechanisms that drive circadian rhythms. They consist of three major components:...

lag, desynchronosis, or circadian dysrhythmia, is a temporary physiological condition that occurs when a person's circadian rhythm is out of sync with the...

Irregular sleep–wake rhythm disorder (ISWRD) is a rare form of circadian rhythm sleep disorder. It is characterized by numerous naps throughout the 24-hour...

a person's circadian rhythm (biological clock) compared to those of societal norms. The disorder affects the timing of biological rhythms including sleep...

blue-green algae, see bacterial circadian rhythms). The best studied rhythm in chronobiology is the circadian rhythm, a roughly 24-hour cycle shown by...

Non-24-hour sleep–wake disorder (non-24 or N24SWD) is one of several chronic circadian rhythm sleep disorders (CRSDs). It is defined as a "chronic steady pattern...

A chronotype is the behavioral manifestation of underlying circadian rhythm's myriad of physical processes. A person's chronotype is the propensity for...

Bacterial circadian rhythms, like other circadian rhythms, are endogenous "biological clocks" that have the following three characteristics: (a) in constant...

the optic chiasm. It is the principal circadian pacemaker in mammals, responsible for generating circadian rhythms. Reception of light inputs from photosensitive...

preceding falling asleep, the condition of being in a drowsy state due to circadian rhythm disorders, or a symptom of other health problems. It can be accompanied...

crucial role in regulating the sleep-wake cycle, also known as the circadian rhythm, in vertebrates. In vertebrates, melatonin's functions extend to synchronizing...

chronobiology, an ultradian rhythm is a recurrent period or cycle repeated throughout a 24-hour day. In contrast, circadian rhythms complete one cycle daily...

sleepwalking and rapid eye movement sleep behavior disorder; bruxism; and circadian rhythm sleep disorders. The use of artificial light has substantially altered...

circadian rhythm can lead to extremely harmful affects on students' learning and memory processes as well. This is largely in part because circadian rhythm...

biological rhythms such as circadian and circannual rhythms to continue natural functions. Different animals will manage their circadian rhythm differently...

sundowning have not been empirically proven, some evidence suggests that circadian rhythm disruption increases sundowning behaviors. In humans, sunset triggers...

approximately 24 hours and maintains this rhythm in the absence of external stimuli is considered a circadian rhythm. It is believed that the brain's suprachiasmatic...

blue-green algae, see bacterial circadian rhythms). The best studied rhythm in chronobiology is the circadian rhythm, a roughly 24-hour cycle shown by...

suprachiasmatic nuclei (SCN), the location of the 'master circadian pacemaker'. See SCN and circadian rhythm below. VIP in the pituitary helps to regulate prolactin...

Sleep disorders are broadly classified into dyssomnias, parasomnias, circadian rhythm sleep disorders involving the timing of sleep, and other disorders...

327.30 Circadian rhythm sleep disorder, unspecified 327.31 Circadian rhythm sleep disorder, delayed sleep phase type 327.32 Circadian rhythm sleep disorder...

animals that are sensitive to blue light. They are involved in the circadian rhythms and the sensing of magnetic fields in a number of species. The name...

Drosophila circadian rhythm is a daily 24-hour cycle of rest and activity in the fruit flies of the genus Drosophila. The biological process was discovered...

factor that is known to affect both the persistence and period of circadian rhythms. Research shows that the CLOCK gene plays a major role as an activator...

Shift work sleep disorder (SWSD) is a circadian rhythm sleep disorder characterized by insomnia, excessive sleepiness, or both affecting people whose work...

social rhythm therapy (IPSRT) is an intervention for people with bipolar disorder (BD). Its primary focus is stabilizing the circadian rhythm disruptions...

Acetabularia has been used to study circadian rhythms. Studies have shown Acetabularia has a diurnal circadian rhythm. These rhythmic changes in respiratory...