Concept
Concept
Circadian rhythms are natural, internal processes that regulate the sleep-wake cycle and repeat roughly every 24 hours, influencing various physiological functions in living organisms. These rhythms are driven by a biological clock and can be affected by environmental cues like light and temperature, impacting overall health and well-being.
Concept
Photoperiodism is the physiological reaction of organisms to the length of day or night, which is crucial in regulating seasonal activities such as flowering in plants and breeding in animals. It involves the perception of light duration by specific receptors and the subsequent signaling pathways that trigger developmental processes.
Concept
The Suprachiasmatic Nucleus (SCN) is a tiny region in the brain's hypothalamus responsible for regulating circadian rhythms, effectively serving as the body's internal clock. It synchronizes daily physiological and behavioral cycles to the 24-hour day-night cycle using light cues received through the retina.
Concept
Melatonin secretion is primarily regulated by the circadian rhythm and is influenced by the light-dark cycle, with levels peaking during the night to promote sleep. This hormone, produced by the pineal gland, plays a crucial role in regulating sleep-wake cycles and can be affected by factors such as age, lifestyle, and exposure to artificial light.
Concept
Entrainment is the synchronization of an organism's internal biological rhythms with external environmental cues, such as light-dark cycles. This process is crucial for maintaining circadian rhythms, which regulate sleep-wake cycles, hormone release, and other physiological processes.
Concept
A Zeitgeber is an external or environmental cue that helps synchronize an organism's internal biological clock to the Earth's 24-hour light-dark cycle. The most powerful Zeitgeber for humans is natural light, which influences circadian rhythms, impacting sleep, alertness, and various physiological processes.
Concept
Chronobiology is the study of biological rhythms and how they are governed by internal clocks and external cues such as light and temperature. It examines how these rhythms influence physiological processes, behaviors, and health across different organisms.
Concept
Seasonal Affective Disorder (SAD) is a type of depression that occurs at a specific time of year, usually in the winter, due to reduced sunlight exposure affecting the body's internal clock and serotonin levels. Treatment often involves light therapy, medication, and psychotherapy to alleviate symptoms and improve mood regulation.
Concept
Light therapy, also known as phototherapy, is a treatment that uses specific wavelengths of light to address various medical and psychological conditions, most commonly Seasonal Affective Disorder (SAD). It works by mimicking natural sunlight, thereby influencing the body's circadian rhythms and regulating mood-related neurotransmitters.
Concept
Retinal ganglion cells are crucial neurons in the retina that transmit visual information from photoreceptors to the brain via the optic nerve. They play a vital role in processing visual signals and are involved in various aspects of vision, including contrast sensitivity, motion detection, and circadian rhythm regulation.
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