A bed sheet is a piece of cloth A textile is a flexible material consisting of a network of natural or artificial fibres often referred to as thread or yarn. Yarn is produced by spinning raw wool fibres, linen, cotton, or other material on a spinning wheel to produce long strands. Textiles are formed by weaving, knitting, crocheting, knotting, or pressing fibres together used to cover a mattress The word mattress is derived from Arabic words meaning "to throw" and "place where something is thrown" or "mat, cushion." During the Crusades, Europeans adopted the Arabic method of sleeping on cushions thrown on the floor, and the word materas eventually descended into Middle English through the Romance languages. It is this sheet that one typically lies on.
In many areas of the world, a second flat bed sheet is laid on top of the sheet covering the mattress. This is known as a "top sheet" and when a top sheet is used, the sheet covering the mattress is known as a "bottom sheet". One sleeps between the two bed sheets. Blankets, comforters, and other bed covers are then placed on top of the second bed sheet.
Bed sheets come in two main varieties--flat or fitted. A flat bed sheet is simply a rectangular sheet of cloth, while a fitted bed sheet has its four corners, and sometimes two or four sides, fitted with elastic An elastomer is a polymer with the property of elasticity. The term, which is derived from elastic polymer, is often used interchangeably with the term rubber, although the latter is preferred when referring to vulcanisates. Each of the monomers which link to form the polymer is usually made of carbon, hydrogen, oxygen and/or silicon. Elastomers, to be used only as a bottom sheet. The purpose of a fitted bottom sheet is to keep it from slipping off the mattress while the bed is in use. A particular way of folding and tucking while making the bed, known as "hospital corners," is sometimes used when the bottom sheet is flat rather than fitted.
Bed sheets were traditionally white, but now various colors and patterns are used. The quality of bed sheets is often conveyed by the thread count Denier is a unit of measure for the linear mass density of fibers. It is defined as the mass in grams per 9,000 meters. In the International System of Units the tex is used instead - the number of threads per square inch of material. In general, the higher the thread count, the softer the sheet, but the weave and type of thread may affect the "hand" of the material so that a sheet with a lower thread count may actually be softer than one with a higher count.
Changing
James Garfield James Abram Garfield was the 20th President of the United States. His death, two months after being shot and six months after his inauguration, made his tenure the second shortest (after William Henry Harrison) in United States history's bedclothes after his shooting.
Common materials include cotton Cotton is a soft, staple fiber that grows in a form known as a boll around the seeds of the cotton plant, a shrub native to tropical and subtropical regions around the world, including the Americas, India and Africa. The fiber most often is spun into yarn or thread and used to make a soft, breathable textile, which is the most widely used natural-, linen Linen is a textile made from the fibers of the flax plant, Linum usitatissimum. Linen is labor-intensive to manufacture, but when it is made into garments, it is valued for its exceptional coolness and freshness in hot weather, and blends of cotton and polyester Polyester is a category of polymers which contain the ester functional group in their main chain. Although there are many polyesters, the term "polyester" as a specific material most commonly refers to polyethylene terephthalate . Polyesters include naturally-occurring chemicals, such as in the cutin of plant cuticles, as well as. Other materials sometimes seen are silk Silk is a natural protein fiber, some forms of which can be woven into textiles. The best-known type of silk is obtained from cocoons made by the larvae of the mulberry silkworm Bombyx mori reared in captivity . The shimmering appearance of silk is due to the triangular prism-like structure of the silk fiber which allows silk cloth to refract, rayon Rayon is a manufactured regenerated cellulose fiber. Because it is produced from naturally occurring polymers, it is neither a truly synthetic fiber nor a natural fiber; it is a semi-synthetic fiber. Rayon is known by the names viscose rayon and art silk in the textile industry. It usually has a high lustre quality giving it a bright sheen. Rayon, and bamboo Bamboo listen are a group of perennial evergreen (except for certain temperate species) plants in the true grass family Poaceae, subfamily Bambusoideae, tribe Bambuseae. Giant bamboos are the largest members of the grass family fiber. New materials as nonwoven polypropylene Polypropylene or polypropene is a thermoplastic polymer, made by the chemical industry and used in a wide variety of applications, including packaging, textiles (e.g. ropes, thermal underwear and carpets), stationery, plastic parts and reusable containers of various types, laboratory equipment, loudspeakers, automotive components, and polymer fabric thanks to their low price allows the bed sheet to be disposabled. Once used in emergency shelters or hospitals this disposable bed sheet is now used as well in hotels.
Usually a flat bed sheet is overlocked An overlock stitch sews over the edge of one or two pieces of cloth for edging, hemming or seaming. Usually an overlock sewing machine will cut the edges of the cloth as they are fed through , though some are made without cutters. The inclusion of automated cutters allows overlock machines to create finished seams easily and quickly. An overlock around the edges to form four seams. One of the seams is wider than the other three and helps with orienting the sheet correctly on the mattress The word mattress is derived from Arabic words meaning "to throw" and "place where something is thrown" or "mat, cushion." During the Crusades, Europeans adopted the Arabic method of sleeping on cushions thrown on the floor, and the word materas eventually descended into Middle English through the Romance languages. The wider seam goes at the head end of the mattress The word mattress is derived from Arabic words meaning "to throw" and "place where something is thrown" or "mat, cushion." During the Crusades, Europeans adopted the Arabic method of sleeping on cushions thrown on the floor, and the word materas eventually descended into Middle English through the Romance languages. Sometimes the sides do not have seams, but are finished with the selvedge only.
When making a bed, the patterned or monogrammed A monogram is a motif made by overlapping or combining two or more letters or other graphemes to form one symbol. Monograms are often made by combining the initials of an individual or a company, used as recognizable symbols or logos. A series of uncombined initials is properly referred to as a cypher and is not a monogram, although ciphers are side of the top sheet is placed facing down and then the top edge is folded towards the foot of the bed, exposing the design.
See also
| Psychophysiology Psychophysiology is the branch of psychology that is concerned with the physiological bases of psychological processes. What used to be known as cognitive psychophysiology until the mid 1990's is currently called Cognitive neuroscience: Sleep Sleep is a naturally recurring state of relatively suspended sensory and motor activity, characterized by total or partial unconsciousness and the inactivity of nearly all voluntary muscles. It is distinguished from quiet wakefulness by a decreased ability to react to stimuli, and it is more easily reversible than hibernation or coma. It is (G47 Meningitis/Arachnoiditis: Bacterial · Viral (Herpesviral) · Fungal (Cryptococcal) · Aseptic (Drug-induced), 327 Meningitis/Arachnoiditis: Bacterial · Viral (Herpesviral) · Fungal (Cryptococcal) · Aseptic (Drug-induced)) |
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| Sleep stages |
Rapid eye movement sleep Rapid eye movement sleep is a normal stage of sleep characterized by the rapid movement of the eyes. REM sleep is classified into two categories: tonic and phasic. It was identified and defined by Kleitman and Aserinsky in the early 1950s · Non-rapid eye movement sleep The sleep stages 1 through 3, previously known as stages 1 through 4, are collectively referred to as NREM, non-rapid eye movement, sleep. Rapid eye movement is not included. There are distinct electroencephalographic and other characteristics seen in each stage. Unlike REM sleep, there is usually little or no eye movement during this stage · Slow-wave sleep Slow-wave sleep , often referred to as deep sleep, consists of stages three and four of non-rapid eye movement sleep, according to the Rechtschaffen & Kales (R&K) standard of 1968. As of 2008, the American Academy of Sleep Medicine (AASM) has discontinued the use of stage 4, such that the previous stages 3 and 4 now are combined as stage 3
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| Brain waves Electroencephalography is the recording of electrical activity along the scalp produced by the firing of neurons within the brain. In clinical contexts, EEG refers to the recording of the brain's spontaneous electrical activity over a short period of time, usually 20–40 minutes, as recorded from multiple electrodes placed on the scalp. In |
Alpha wave Alpha waves are electromagnetic oscillations in the frequency range of 8–12 Hz arising from synchronous and coherent electrical activity of thalamic pacemaker cells. They are also called Berger's wave in memory of the founder of EEG · Beta wave Beta wave, or beta rhythm, is the term used to designate the frequency range of brain activity between 12 and 30 Hz . Beta waves are split into three sections: High Beta Waves (19Hz+); Beta Waves (15-18Hz); and Low Beta Waves (12-15Hz). Beta states are the states associated with normal waking consciousness · Gamma wave A gamma wave is a pattern of brain waves, with a frequency between 25 to 100 Hz, though 40 Hz is prototypical. According to a popular 20 year old theory, these waves may be implicated in creating the unity of conscious perception . However, there is no agreement on the theory; as a researcher suggests: · Delta wave A delta wave is a high amplitude brain wave with a frequency of 1–4 Hertz which can be recorded with an electroencephalogram and is usually associated with slow-wave sleep · Theta rhythm A theta rhythm is an oscillatory pattern in EEG signals recorded either from inside the brain or from electrodes glued to the scalp. Two types of theta rhythm have been described. The "hippocampal theta rhythm" is a strong oscillation that can be observed in the hippocampus and other brain structures in numerous species of mammals · K-complex A K-complex is an electroencephalography waveform that occurs during stage 2 of NREM sleep. It is the "largest event in healthy human EEG". It consists of a brief negative high-voltage peak, usually greater than 100 µV, followed by a slower positive complex around 350 and 550 ms and at 900ms a final negative peak. K-complexes occur
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| Sleep disorders A sleep disorder is a medical disorder of the sleep patterns of a person or animal. Some sleep disorders are serious enough to interfere with normal physical, mental and emotional functioning. A test commonly ordered for some sleep disorders is the polysomnogram |
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Dyssomnia Patients may complain of difficulty getting to sleep or staying asleep, intermittent wakefulness during the night, early morning awakening, or combinations of any of these. Transient episodes are usually of little significance. Stress, caffeine, physical discomfort, daytime napping, and early bedtimes are common factors
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Insomnia Insomnia is a symptom which can accompany of any of several sleep, medical and psychiatric disorders, characterized by persistent difficulty falling asleep and/or staying asleep despite the opportunity. Insomnia is typically followed by functional impairment while awake. Both organic and non-organic insomnia without other cause constitute a sleep · Narcolepsy Narcolepsy is a chronic sleep disorder, or dyssomnia. The condition is characterized by excessive daytime sleepiness in which a person experiences extreme fatigue and possibly falls asleep at inappropriate times, such as while at work or at school. A narcoleptic will most likely experience disturbed nocturnal sleep and also abnormal daytime sleep · Sleep apnea Sleep apnea is a sleep disorder characterized by pauses in breathing during sleep. Each episode, called an apnea (Greek: ἄπνοια (ápnoia), from α- (a-), privative, πνέειν (pnéein), to breathe), lasts long enough so that one or more breaths are missed, and such episodes occur repeatedly throughout sleep. The standard definition of (Obesity hypoventilation syndrome Obesity hypoventilation syndrome is a condition in which severely overweight people fail to breathe rapidly enough or deeply enough, resulting in low blood oxygen levels and high blood carbon dioxide (CO2) levels. Many people with this condition also frequently stop breathing altogether for short periods of time during sleep (obstructive sleep, Ondine's curse Ondine's Curse , also called congenital central hypoventilation syndrome (CCHS) or primary alveolar hypoventilation, is a respiratory disorder that is fatal if untreated. Persons afflicted with Ondine's curse classically suffer from respiratory arrest during sleep) · Hypersomnia Hypersomnia can be caused by brain damage and disorders such as clinical depression, uremia and fibromyalgia. Hypersomnia can also be a symptom of other sleep disorders such as narcolepsy, sleep apnea, restless leg syndrome and periodic limb movement disorder. It may also occur as a side effect of taking certain medications , of withdrawal from · Circadian rhythm sleep disorder Circadian rhythm sleep disorders are a family of sleep disorders affecting, among other things, the timing of sleep. People with circadian rhythm sleep disorders are unable to sleep and wake at the times required for normal work, school, and social needs. They are generally able to get enough sleep if allowed to sleep and wake at the times (Advanced sleep phase syndrome Advanced sleep phase syndrome , also known as the advanced sleep-phase type (ASPT) of circadian rhythm sleep disorder, is a condition in which patients feel very sleepy and go to bed early in the evening (e.g. 18:00-20:00) and wake up very early in the morning (e.g. 01:00-03:00), Delayed sleep phase syndrome Delayed sleep-phase syndrome , also known as delayed sleep-phase disorder (DSPD) or delayed sleep-phase type (DSPT), is a circadian rhythm sleep disorder, a chronic disorder of the timing of sleep, peak period of alertness, core body temperature, hormonal and other daily rhythms relative to societal norms. People with DSPS tend to fall asleep some, Non-24-hour sleep-wake syndrome Non-24-hour sleep-wake syndrome is a chronic circadian rhythm sleep disorder, classified within Chapter VI, Diseases of the Nervous System, in the ICD-10. It can be defined as "a chronic steady pattern comprising one- to two-hour daily delays in sleep onset and wake times in an individual living in society." The pattern of delay persists, Jet lag Jet lag medically referred to as "desynchronosis" is a physiological condition which is a consequence of alterations to circadian rhythms; it is classified as one of the circadian rhythm sleep disorders. Jet lag results from rapid long-distance transmeridian travel, as on a jet plane)
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Parasomnia Parasomnias are a category of sleep disorders that involve abnormal and unnatural movements, behaviors, emotions, perceptions, and dreams that occur while falling asleep, sleeping, between sleep stages, or arousal from sleep. Most parasomnias are dissociated sleep states which are partial arousals during the transitions between wakefulness and
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Night terror A night terror, also known as a sleep terror or pavor nocturnus, is a parasomnia disorder characterized by extreme terror and a temporary inability to regain full consciousness. The subject wakes abruptly from slow-wave sleep, with waking usually accompanied by gasping, moaning, or screaming. It is often impossible to awaken the person fully, and · Sleepwalking Sleepwalking is a parasomnia (not to be confused with psychosis) or sleep disorder where the sufferer engages in activities normally associated with wakefulness while asleep or in a sleep-like state. Sleepwalking is usually defined by or involves the person affected apparently shifting from their prior sleeping position and moving around and · Somniloquy Somniloquy or sleep-talking is a parasomnia that refers to talking aloud in one's sleep. It can be quite loud, ranging from simple sounds to long speeches, and can occur many times during sleep. Listeners may or may not be able to understand what the person is saying
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Other/ungrouped
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Night eating syndrome · Nocturia · Nocturnal myoclonus · Sleep deprivation
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| Benign phenomena |
Dream · Exploding head syndrome · False awakening · Hypnagogia · Hypnic jerk · Lucid dream · Nightmare · Nocturnal emission · Sleep paralysis · Somnolence
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| Related topics |
Bed (Bunk bed, Four poster bed, Futon, Hammock, Mattress) · Bed bug · Bedding · Bedroom · Bedtime · Bedtime toy · Bedtime story · Caffeine nap · Chronotype · Dream journal · Hypnopompic state · Lullaby · Methods of falling asleep · Nap · Nightwear · Polyphasic sleep · Polysomnography · Power nap · Siesta · Sleep and creativity · Sleep and learning · Sleep debt · Sleep diary · Sleep inertia · Sleep medicine · Sleeping while on duty · Sleepover · Snoring · Excessive daytime sleepiness · ("Sleeping sickness", which is not a sleep disorder.)
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Categories: Bedding | Linens
