Muscle toneIn physiology, medicine, and anatomy, muscle tone (residual muscle tension or tonus) is the continuous and passive partial contraction of the muscles, or the muscle's resistance to passive stretch during resting state. It helps to maintain posture and declines during REM sleep. Muscle tone is regulated by the activity of the motor neurons and can be affected by various factors, including age, disease, and nerve damage.
Excessive daytime sleepinessExcessive daytime sleepiness (EDS) is characterized by persistent sleepiness and often a general lack of energy, even during the day after apparently adequate or even prolonged nighttime sleep. EDS can be considered as a broad condition encompassing several sleep disorders where increased sleep is a symptom, or as a symptom of another underlying disorder like narcolepsy, circadian rhythm sleep disorder, sleep apnea or idiopathic hypersomnia.
Lucid dreamA lucid dream is a type of dream in which the dreamer becomes aware that they are dreaming while dreaming. During a lucid dream, the dreamer may gain some amount of control over the dream characters, narrative, or environment. Lucid dreaming has been studied and reported for many years. Prominent figures from ancient to modern times have been fascinated by lucid dreams and have sought ways to better understand their causes and purpose. Many different theories have emerged as a result of scientific research on the subject and have even been shown in pop culture.
Treatment and control groupsIn the design of experiments, hypotheses are applied to experimental units in a treatment group. In comparative experiments, members of a control group receive a standard treatment, a placebo, or no treatment at all. There may be more than one treatment group, more than one control group, or both. A placebo control group can be used to support a double-blind study, in which some subjects are given an ineffective treatment (in medical studies typically a sugar pill) to minimize differences in the experiences of subjects in the different groups; this is done in a way that ensures no participant in the experiment (subject or experimenter) knows to which group each subject belongs.
Delayed onset muscle sorenessDelayed onset muscle soreness (DOMS) is the pain and stiffness felt in muscles after unaccustomed or strenuous exercise. The soreness is felt most strongly 24 to 72 hours after the exercise. It is thought to be caused by eccentric (lengthening) exercise, which causes small-scale damage (microtrauma) to the muscle fibers. After such exercise, the muscle adapts rapidly to prevent muscle damage, and thereby soreness, if the exercise is repeated. Delayed onset muscle soreness is one symptom of exercise-induced muscle damage.
PolysomnographyPolysomnography (PSG), a type of sleep study, is a multi-parameter study of sleep and a diagnostic tool in sleep medicine. The test result is called a polysomnogram, also abbreviated PSG. The name is derived from Greek and Latin roots: the Greek πολύς (polus for "many, much", indicating many channels), the Latin somnus ("sleep"), and the Greek γράφειν (graphein, "to write"). Type I polysomnography is a sleep study performed overnight while being continuously monitored by a credentialed technologist.
Sleep paralysisSleep paralysis is a state, during waking up or falling asleep, in which one is conscious but is unable to move or speak. During an episode, one may hallucinate (hear, feel, or see things that are not there), which often results in fear. Episodes generally last no more than a few minutes. It can recur multiple times or occur as a single episode. The condition may occur in those who are otherwise healthy or those with narcolepsy, or it may run in families as a result of specific genetic changes.
Neuromuscular junctionA neuromuscular junction (or myoneural junction) is a chemical synapse between a motor neuron and a muscle fiber. It allows the motor neuron to transmit a signal to the muscle fiber, causing muscle contraction. Muscles require innervation to function—and even just to maintain muscle tone, avoiding atrophy. In the neuromuscular system nerves from the central nervous system and the peripheral nervous system are linked and work together with muscles.
StrokeA stroke is a medical condition in which poor blood flow to the brain causes cell death. There are two main types of stroke: ischemic, due to lack of blood flow, and hemorrhagic, due to bleeding. Both cause parts of the brain to stop functioning properly. Signs and symptoms of a stroke may include an inability to move or feel on one side of the body, problems understanding or speaking, dizziness, or loss of vision to one side. Signs and symptoms often appear soon after the stroke has occurred.
SelegilineSelegiline, also known as L-deprenyl and sold under the brand names Eldepryl and Emsam among others, is a medication which is used in the treatment of Parkinson's disease and major depressive disorder. It is provided in the form of a capsule or tablet taken by mouth for Parkinson's disease and as a patch applied to skin for depression. Selegiline acts as a monoamine oxidase inhibitor, and increases levels of monoamine neurotransmitters in the brain.
SarcopeniaSarcopenia is a type of muscle loss (muscle atrophy) that occurs with aging and/or immobility. It is characterized by the degenerative loss of skeletal muscle mass, quality, and strength. The rate of muscle loss is dependent on exercise level, co-morbidities, nutrition and other factors. The muscle loss is related to changes in muscle synthesis signalling pathways. It is distinct from cachexia, in which muscle is degraded through cytokine-mediated degradation, although both conditions may co-exist.
Human eyeThe human eye is a sensory organ, part of the sensory nervous system, that reacts to visible light and allows humans to use visual information for various purposes including seeing things, keeping balance, and maintaining circadian rhythm. The eye can be considered as a living optical device. It is approximately spherical in shape, with its outer layers, such as the outermost, white part of the eye (the sclera) and one of its inner layers (the pigmented choroid) keeping the eye essentially light tight except on the eye's optic axis.
