Search results
Results from the WOW.Com Content Network
Sleep can follow a physiological or behavioral definition. In the physiological sense, sleep is a state characterized by reversible unconsciousness, special brainwave patterns, sporadic eye movement, loss of muscle tone (possibly with some exceptions; see below regarding the sleep of birds and of aquatic mammals), and a compensatory increase following deprivation of the state, this last known ...
The neuroscience of sleep is the study of the neuroscientific and physiological basis of the nature of sleep and its functions. Traditionally, sleep has been studied as part of psychology and medicine. [1] The study of sleep from a neuroscience perspective grew to prominence with advances in technology and the proliferation of neuroscience ...
A circadian rhythm (/ sərˈkeɪdiən /), or circadian cycle, is a natural oscillation that repeats roughly every 24 hours. Circadian rhythms can refer to any process that originates within an organism (i.e., endogenous) and responds to the environment (is entrained by the environment). Circadian rhythms are regulated by a circadian clock whose ...
Sleep. Sleeping Girl, Domenico Fetti, c. 1615. Sleep is a state of reduced mental and physical activity in which consciousness is altered and certain sensory activity is inhibited. During sleep, there is a marked decrease in muscle activity and interactions with the surrounding environment.
Melatonin, an indoleamine, is a natural compound produced by various organisms, including bacteria and eukaryotes. [1] Its discovery in 1958 by Aaron B. Lerner and colleagues stemmed from the isolation of a substance from the pineal gland of cows that could induce skin lightening in common frogs.
Slow-wave sleep (SWS), also known as Stage 3, is characterized by a lack of movement and difficulty of arousal. Slow-wave sleep occurring in both hemispheres is referred to as bihemispheric slow-wave sleep (BSWS) and is common among most animals. Slow-wave sleep contrasts with rapid eye movement sleep (REM), which can only occur simultaneously ...
Rapid eye movement sleep (REM sleep or REMS) is a unique phase of sleep in mammals (including humans) and birds, characterized by random rapid movement of the eyes, accompanied by low muscle tone throughout the body, and the propensity of the sleeper to dream vividly. The REM phase is also known as paradoxical sleep (PS) and sometimes ...
The brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It consists of nervous tissue and is typically located in the head (cephalization), usually near organs for special senses such as vision, hearing and olfaction. Being the most specialized organ, it is responsible for receiving ...