text:
For other uses, see Hair (disambiguation).
"Hairy" redirects here. For the epithet, see List of people known as the Hairy.
"Glabrousness" redirects here. For other uses, see Glabrousness (disambiguation).
Cross section of a hair strand
Scanning electron microscopy image of Merino wool (top) and human hair (bottom) showing keratin scales.
H3.12.00.3.02001
Anatomical terminology
Hair is a protein filament that grows from follicles found in the dermis. Hair is one of the defining characteristics of mammals; the human body, apart from areas of glabrous skin, is covered in follicles which produce thick terminal and fine vellus hair. Most common interest in hair is focused on hair growth, hair types, and hair care, but hair is also an important biomaterial primarily composed of protein, notably alpha-keratin.
Attitudes towards different forms of hair, such as hairstyles and hair removal, vary widely across different cultures and historical periods, but it is often used to indicate a person's personal beliefs or social position, such as their age, sex, or religion.[1]
2.1 Root of the hair
2.2 Natural color
2.3 Human hair growth
2.4 Texture
2.4.1 Classification systems
3 Functions
3.1 Warmth
3.2 Protection
3.3 Touch sense
3.3.1 Eyebrows and eyelashes
4 Evolution
4.1 Human hairlessness
4.2 Evolutionary variation
4.3.1 Curly hair
4.3.2 The EDAR locus
6.1 Removal practices
6.1.1 Shaving
6.1.2 Waxing
6.1.3 Laser removal
6.1.4 Cutting and trimming
7 Social role
7.1 Indication of status
7.2 Religious practices
The word "hair" usually refers to two distinct structures:
the part beneath the skin, called the hair follicle, or, when pulled from the skin, the bulb. This organ is located in the dermis and maintains stem cells, which not only re-grow the hair after it falls out, but also are recruited to regrow skin after a wound.[2]
the shaft, which is the hard filamentous part that extends above the skin surface. A cross section of the hair shaft may be divided roughly into three zones.
Hair fibers have a structure consisting of several layers, starting from the outside:
the cuticle, which consists of several layers of flat, thin cells laid out overlapping one another as roof shingles
the cortex, which contains the keratin bundles in cell structures that remain roughly rod-like
the medulla, a disorganized and open area at the fiber's center[3]
Each strand of hair is made up of the medulla, cortex, and cuticle;[4] the innermost region, the medulla, is not always present and is an open, unstructured region.[5] The highly structural and organized cortex, or second of three layers of the hair, is the primary source of mechanical strength and water uptake; the cortex contains melanin, which colors the fiber based on the number, distribution and types of melanin granules. The shape of the follicle determines the shape of the cortex, and the shape of the fiber is related to how straight or curly the hair is. People with straight hair have round hair fibers. Oval and other shaped fibers are generally more wavy or curly; the cuticle is the outer covering. Its complex structure slides as the hair swells and is covered with a single molecular layer of lipid that makes the hair repel water;[4] the diameter of human hair varies from 0.017 to 0.18 millimeters (0.00067 to 0.00709 in).[6] There are two million small, tubular glands and sweat glands that produce watery fluids that cool the body by evaporation; the glands at the opening of the hair produce a fatty secretion that lubricates the hair.[7]
Hair growth begins inside the hair follicle; the only "living" portion of the hair is found in the follicle. The hair that is visible is the hair shaft, which exhibits no biochemical activity and is considered "dead"; the base of a hair's root (the "bulb") contains the cells that produce the hair shaft.[8] Other structures of the hair follicle include the oil producing sebaceous gland which lubricates the hair and the arrector pili muscles, which are responsible for causing hairs to stand up. In humans with little body hair, the effect results in goose bumps.
Root of the hair
Section of skin, showing the epidermis and dermis; a hair in its follicle; the Arrector pili muscle; sebaceous glands.
radix pili
The root of the hair ends in an enlargement, the hair bulb, which is whiter in color and softer in texture than the shaft, and is lodged in a follicular involution of the epidermis called the hair follicle; the bulb of hair consists of fibrous connective tissue, glassy membrane, external root sheath, internal root sheath composed of epithelium stratum (Henle's layer) and granular stratum (Huxley's layer), cuticle, cortex and medulla.[9]
Main article: Human hair color
A woman with dark blonde hair, the basal color appears brown due to higher levels of brownish eumelanin.
All natural hair colors are the result of two types of hair pigments. Both of these pigments are melanin types, produced inside the hair follicle and packed into granules found in the fibers. Eumelanin is the dominant pigment in brown hair and black hair, while pheomelanin is dominant in red hair. Blond hair is the result of having little pigmentation in the hair strand. Gray hair occurs when melanin production decreases or stops, while poliosis is hair (and often the skin to which the hair is attached), typically in spots, that never possessed melanin at all in the first place, or ceased for natural genetic reasons, generally, in the first years of life.
Human hair growth
Main article: Human hair growth
Hair grows everywhere on the external body except for mucus membranes and glabrous skin, such as that found on the palms of the hands, soles of the feet, and lips.
Hair follows a specific growth cycle with three distinct and concurrent phases: anagen, catagen, and telogen phases; all three occur simultaneously - while one strand of hair may be in the anagen phase, another may be in the telogen phase; each has specific characteristics that determine the length of the hair.
The body has different types of hair, including vellus hair and androgenic hair, each with its own type of cellular construction; the different construction gives the hair unique characteristics, serving specific purposes, mainly, warmth and protection.
Orange American shorthair cat.
Hair exists in a variety of textures. Three main aspects of hair texture are the curl pattern, volume, and consistency; the derivations of hair texture are not fully understood. All mammalian hair is composed of keratin, so the make-up of hair follicles is not the source of varying hair patterns. There are a range of theories pertaining to the curl patterns of hair. Scientists have come to believe that the shape of the hair shaft has an effect on the curliness of the individual's hair. A very round shaft allows for fewer disulfide bonds to be present in the hair strand; this means the bonds present are directly in line with one another, resulting in straight hair.[10]
The flatter the hair shaft becomes, the curlier hair gets, because the shape allows more cysteines to become compacted together resulting in a bent shape that, with every additional disulfide bond, becomes curlier in form;[10] as the hair follicle shape determines curl pattern, the hair follicle size determines thickness. While the circumference of the hair follicle expands, so does the thickness of the hair follicle. An individual's hair volume, as a result, can be thin, normal, or thick; the consistency of hair can almost always be grouped into three categories: fine, medium, and coarse. This trait is determined by the hair follicle volume and the condition of the strand.[11] Fine hair has the smallest circumference, coarse hair has the largest circumference, and medium hair is anywhere between the other two.[11] Coarse hair has a more open cuticle than thin or medium hair causing it to be the most porous.[11]
Classification systems
There are various systems that people use to classify their curl patterns. Being knowledgeable of an individual's hair type is a good start to knowing how to take care of one's hair. There is not just one method to discovering one's hair type. Additionally it is possible, and quite normal to have more than one kind of hair type, for instance having a mixture of both type 3a & 3b curls.
Andre Walker system
The Andre Walker Hair Typing System is the most widely used system to classify hair; the system was created by the hairstylist of Oprah Winfrey, Andre Walker. According to this system there are four types of hair: straight, wavy, curly, kinky.
Type 1 is straight hair, which reflects the most sheen and also the most resilient hair of all of the hair types. It is hard to damage and immensely difficult to curl this hair texture; because the sebum easily spreads from the scalp to the ends without curls or kinks to interrupt its path, it is the most oily hair texture of all.
Type 2 is wavy hair, whose texture and sheen ranges somewhere between straight and curly hair. Wavy hair is also more likely to become frizzy than straight hair. While type A waves can easily alternate between straight and curly styles, type B and C Wavy hair is resistant to styling.
Type 3 is curly hair known to have an S-shape. The curl pattern may resemble a lowercase "s", uppercase "S", or sometimes an uppercase "Z" or lowercase "z".[citation needed] This hair type is usually voluminous, "climate dependent (humidity = frizz), and damage-prone."[citation needed] Lack of proper care causes less defined curls.
Type 4 is kinky hair, which features a tightly coiled curl pattern (or no discernible curl pattern at all) that is often fragile with a very high density. This type of hair shrinks when wet and because it has fewer cuticle layers than other hair types it is more susceptible to damage.
Andre Walker hair types
TYPE 1: Straight
Straight (Fine/Thin) Hair tends to be very soft, shiny, oily and poor at holding curls, but difficult to damage.
Straight (Medium) Hair characterised by volume and body.
Straight (Coarse) Hair tends to be bone-straight and difficult to curl. Common in Asian women.
TYPE 2: Wavy
Wavy (Fine/Thin) Hair has definite "S" pattern and is usually receptive to a variety of styles.
Wavy (Medium) Can tend to be frizzy and a little resistant to styling.
Wavy (Coarse) Frizzy or very frizzy with thicker waves; often more resistant to styling.
TYPE 3: Curly
Curly (Loose) Curly hair that usually presents a definite "S" pattern and tends to combine thickness, fullness, body and/or frizziness.
Curly (Tight) As 3a but with tighter curling like a spiral.
TYPE 4: Kinky
Kinky (Soft) Hair tends to be very fragile, tightly coiled and can feature curly patterning.
Kinky (Wiry) As 4a but with less visible (or no) curly patterning.
Kinky (Wiry) As 4a and 4b but with almost no defined curl pattern.
FIA system
This is a method which classifies the hair by curl pattern, hair-strand thickness and overall hair volume.
FIA hair classification
Curliness
Stick-straight.
Straight but with a slight body wave adding some volume.
Straight with body wave and one or two visible S-waves (e.g. at nape of neck or temples).
Loose with stretched S-waves throughout.
Shorter with more distinct S-waves (resembling e.g. braided damp hair).
Distinct S-waves, some spiral curling.
Big, loose spiral curls.
Bouncy ringlets.
Tight corkscrews.
Very ("Really") curly
Tightly coiled S-curls.
Z-patterned (tightly coiled, sharply angled)
Mostly Z-patterned (tightly kinked, less definition)
Thin strands that sometimes are almost translucent when held up to the light. Shed strands can
be hard to see even against a contrasting background; similar to hair found on many people of
Scandinavian descent. You can also try rolling a strand between your thumb and index finger.
Fine hair is difficult to feel or it feels like an ultra-fine strand of silk.
Strands are neither fine nor coarse; similar to hair found on many Caucasians. You can also try
rolling a strand between your thumb and index finger. Medium hair feels like a cotton thread.
You can feel it, but it isn't stiff or rough. It is neither fine nor coarse.
Thick strands whose shed strands usually are easily identified against most backgrounds;
similar to hair found on many people of Asian or Native American descent. You can also try
rolling a strand between your thumb and index finger. Coarse hair feels hard and wiry.
As you roll it back and forth, you may hear it.
by circumference of full-hair ponytail
Thin circumference less than 2 inches (5 centimetres)
Normal ... from 2 to 4 inches (5 to 10 centimetres)
Thick ... more than 4 inches (10 centimetres)
Many mammals have fur and other hairs that serve different functions. Hair provides thermal regulation and camouflage for many animals; for others it provides signals to other animals such as warnings, mating, or other communicative displays; and for some animals hair provides defensive functions and, rarely, even offensive protection. Hair also has a sensory function, extending the sense of touch beyond the surface of the skin. Guard hairs give warnings that may trigger a recoiling reaction.
Polar bears use their fur for warmth and while their skin is black, their transparent fur appears white and provides camouflage while hunting and serves as protection by hiding cubs in the snow.
While humans have developed clothing and other means of keeping warm, the hair found on the head serves primarily as a source of heat insulation and cooling (when sweat evaporates from soaked hair) as well as protection from ultra-violet radiation exposure; the function of hair in other locations is debated. Hats and coats are still required while doing outdoor activities in cold weather to prevent frostbite and hypothermia, but the hair on the human body does help to keep the internal temperature regulated; when the body is too cold, the arrector pili muscles found attached to hair follicles stand up, causing the hair in these follicles to do the same. These hairs then form a heat-trapping layer above the epidermis; this process is formally called piloerection, derived from the Latin words 'pilus' ('hair') and 'erectio' ('rising up'), but is more commonly known as 'having goose bumps' in English.[12] This is more effective in other mammals whose fur fluffs up to create air pockets between hairs that insulate the body from the cold; the opposite actions occur when the body is too warm; the arrector muscles make the hair lie flat on the skin which allows heat to leave.
In some mammals, such as hedgehogs and porcupines, the hairs have been modified into hard spines or quills; these are covered with thick plates of keratin and serve as protection against predators. Thick hair such as that of the lion's mane and grizzly bear's fur do offer some protection from physical damages such as bites and scratches.
Touch sense
Displacement and vibration of hair shafts are detected by hair follicle nerve receptors and nerve receptors within the skin. Hairs can sense movements of air as well as touch by physical objects and they provide sensory awareness of the presence of ectoparasites;[13] some hairs, such as eyelashes, are especially sensitive to the presence of potentially harmful matter.[14][15][16][17]
Eyebrows and eyelashes
Eyelashes and eyebrows help to protect the eyes from dust, dirt, and sweat.
The eyebrows provide moderate protection to the eyes from dirt, sweat and rain, they also play a key role in non-verbal communication by displaying emotions such as sadness, anger, surprise and excitement. In many other mammals, they contain much longer, whisker-like hairs that act as tactile sensors.
The eyelash grows at the edges of the eyelid and protects the eye from dirt; the eyelash is to humans, camels, horses, ostriches etc., what whiskers are to cats; they are used to sense when dirt, dust, or any other potentially harmful object is too close to the eye.[18] The eye reflexively closes as a result of this sensation.
Hair has its origins in the common ancestor of mammals, the synapsids, about 300 million years ago, it is currently unknown at what stage the synapsids acquired mammalian characteristics such as body hair and mammary glands, as the fossils only rarely provide direct evidence for soft tissues. Skin impression of the belly and lower tail of a pelycosaur, possibly Haptodus shows the basal synapsid stock bore transverse rows of rectangular scutes, similar to those of a modern crocodile.[19] An exceptionally well-preserved skull of Estemmenosuchus, a therapsid from the Upper Permian, shows smooth, hairless skin with what appears to be glandular depressions,[20] though as a semi-aquatic species it might not have been particularly useful to determine the integument of terrestrial species; the oldest undisputed known fossils showing unambiguous imprints of hair are the Callovian (late middle Jurassic) Castorocauda and several contemporary haramiyidans, both near-mammal cynodonts.[21][22][23] More recently, studies on terminal Permian Russian coprolites may suggest that non-mammalian synapsids from that era had fur.[24] If this is the case, these are the oldest hair remnants known, showcasing that fur occurred as far back as the latest Paleozoic.
Some modern mammals have a special gland in front of each orbit used to preen the fur, called the harderian gland. Imprints of this structure are found in the skull of the small early mammals like Morganucodon, but not in their cynodont ancestors like Thrinaxodon.[25]
The hairs of the fur in modern animals are all connected to nerves, and so the fur also serves as a transmitter for sensory input. Fur could have evolved from sensory hair (whiskers); the signals from this sensory apparatus is interpreted in the neocortex, a chapter of the brain that expanded markedly in animals like Morganucodon and Hadrocodium.[26] The more advanced therapsids could have had a combination of naked skin, whiskers, and scutes. A full pelage likely did not evolve until the therapsid-mammal transition;[27] the more advanced, smaller therapsids could have had a combination of hair and scutes, a combination still found in some modern mammals, such as rodents and the opossum.[28]
The high interspecific variability of the size, color, and microstructure of hair often enables the identification of species based on single hair filaments.[29][30]
Naked mole-rat (Heterocephalus glaber) in a zoo.
In varying degrees most mammals have some skin areas without natural hair. On the human body, glabrous skin is found on the ventral portion of the fingers, palms, soles of feet and lips, which are all parts of the body most closely associated with interacting with the world around us,[31] as are the labia minora and glans penis.[32] There are four main types of mechanoreceptors in the glabrous skin of humans: Pacinian corpuscles, Meissner's corpuscles, Merkel's discs, and Ruffini corpuscles.
The naked mole-rat (Heterocephalus glaber) has evolved skin lacking in general, pelagic hair covering, yet has retained long, very sparsely scattered tactile hairs over its body.[31] Glabrousness is a trait that may be associated with neoteny.[33]
Human hairlessness
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The general hairlessness of humans in comparison to related species may be due to loss of functionality in the pseudogene KRTHAP1 (which helps produce keratin) in the human lineage about 240,000 years ago.[34] On an individual basis, mutations in the gene HR can lead to complete hair loss, though this is not typical in humans.[35] Humans may also lose their hair as a result of hormonal imbalance due to drugs or pregnancy.[36]
In order to comprehend why humans are essentially hairless, it is essential to understand that mammalian body hair is not merely an aesthetic characteristic; it protects the skin from wounds, bites, heat, cold, and UV radiation.[37] Additionally, it can be used as a communication tool and as a camouflage.[38] To this end, it can be concluded that benefits stemming from the loss of human body hair must be great enough to outweigh the loss of these protective functions by nakedness.
Humans are the only primate species that have undergone significant hair loss and of the approximately 5000 extant species of mammal, only a handful are effectively hairless; this list includes elephants, rhinoceroses, hippopotamuses, walruses, some species of pigs, whales and other cetaceans, and naked mole rats.[38] Most mammals have light skin that is covered by fur, and biologists believe that early human ancestors started out this way also. Dark skin probably evolved after humans lost their body fur, because the naked skin was vulnerable to the strong UV radiation as explained in the Out of Africa hypothesis. Therefore, evidence of the time when human skin darkened has been used to date the loss of human body hair, assuming that the dark skin was needed after the fur was gone, it was expected that dating the split of the ancestral human louse into two species, the head louse and the pubic louse, would date the loss of body hair in human ancestors. However, it turned out that the human pubic louse does not descend from the ancestral human louse, but from the gorilla louse, diverging 3.3 million years ago. This suggests that humans had lost body hair (but retained head hair) and developed thick pubic hair prior to this date, were living in or close to the forest where gorillas lived, and acquired pubic lice from butchering gorillas or sleeping in their nests;[39][40] the evolution of the body louse from the head louse, on the other hand, places the date of clothing much later, some 100,000 years ago.[41][42]
The soft, fine hair found on many nonhuman mammals is typically called fur.[43]
The sweat glands in humans could have evolved to spread from the hands and feet as the body hair changed, or the hair change could have occurred to facilitate sweating. Horses and humans are two of the few animals capable of sweating on most of their body, yet horses are larger and still have fully developed fur. In humans, the skin hairs lie flat in hot conditions, as the arrector pili muscles relax, preventing heat from being trapped by a layer of still air between the hairs, and increasing heat loss by convection.
Another hypothesis for the thick body hair on humans proposes that Fisherian runaway sexual selection played a role (as well as in the selection of long head hair), (see types of hair and vellus hair), as well as a much larger role of testosterone in men. Sexual selection is the only theory thus far that explains the sexual dimorphism seen in the hair patterns of men and women. On average, men have more body hair than women. Males have more terminal hair, especially on the face, chest, abdomen, and back, and females have more vellus hair, which is less visible; the halting of hair development at a juvenile stage, vellus hair, would also be consistent with the neoteny evident in humans, especially in females, and thus they could have occurred at the same time.[44] This theory, however, has significant holdings in today's cultural norms. There is no evidence that sexual selection would proceed to such a drastic extent over a million years ago when a full, lush coat of hair would most likely indicate health and would therefore be more likely to be selected for, not against, and not all human populations today have sexual dimorphism in body hair.
A further hypothesis is that human hair was reduced in response to ectoparasites;[45][46] the "ectoparasite" explanation of modern human nakedness is based on the principle that a hairless primate would harbor fewer parasites. When our ancestors adopted group-dwelling social arrangements roughly 1.8 mya, ectoparasite loads increased dramatically. Early humans became the only one of the 193 primate species to have fleas, which can be attributed to the close living arrangements of large groups of individuals. While primate species have communal sleeping arrangements, these groups are always on the move and thus are less likely to harbor ectoparasites; because of this, selection pressure for early humans would favor decreasing body hair because those with thick coats would have more lethal-disease-carrying ectoparasites and would thereby have lower fitness.[citation needed]
Another view is proposed by James Giles, who attempts to explain hairlessness as evolved from the relationship between mother and child, and as a consequence of bipedalism. Giles also connects romantic love to hairlessness.[47]
Another hypothesis is that humans' use of fire caused or initiated the reduction in human hair.[48]
Evolutionary variation
Evolutionary biologists suggest that the genus Homo arose in East Africa approximately 2.5 million years ago.[49] They devised new hunting techniques;[49] the higher protein diet led to the evolution of larger body and brain sizes.[49] Jablonski[49] postulates that increasing body size, in conjunction with intensified hunting during the day at the equator, gave rise to a greater need to rapidly expel heat; as a result, humans evolved the ability to sweat: a process which was facilitated by the loss of body hair.[49] A major problem with this theory,[citation needed] however, is that it does not explain why males are larger, hairier, and were more active in hunting than females. The female-male size differential among other closely associated primates is much greater than among humans, and therefore it was reduced during human evolution. Other primates have sweat gland in their armpits that function as those of humans, and thus it is probable that human sweat glands evolved from a similar distribution, spreading to more areas of the body, rather than occurring through evolution of a new trait, it is not known whether the increased distribution of sweat glands occurred before, during, or after, the change in body hair, or even whether the two are related developments. Horses also sweat, and they are larger, hairier, and expend more energy running than human males, so there may not be any connection between the ability to sweat and the apparent hairlessness of humans.
Another factor in human evolution that also occurred in the prehistoric past was a preferential selection for neoteny, particularly in females; the idea that adult humans exhibit certain neotenous (juvenile) features, not evinced in the great apes, is about a century old. Louis Bolk made a long list of such traits,[50] and Stephen Jay Gould published a short list in Ontogeny and Phylogeny.[51] In addition, paedomorphic characteristics in women are often acknowledged as desirable by men in developed countries.[52] For instance, vellus hair is a juvenile characteristic. However, while men develop longer, coarser, thicker, and darker terminal hair through sexual differentiation, women do not, leaving their vellus hair visible.
Further information: Human evolutionary genetics
Yellow curly hair and scalp from body which had long black wig over hair. Parts of wig plait remains. From Egypt, Gurob, probably tomb 23. 18th–19th Dynasty. The Petrie Museum of Egyptian Archaeology, London
Man with curly hair (David Luiz)
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Jablonski[49] asserts head hair was evolutionarily advantageous for pre-humans to retain because it protected the scalp as they walked upright in the intense African (equatorial) UV light. While some might argue that, by this logic, humans should also express hairy shoulders because these body parts would putatively be exposed to similar conditions, the protection of the head, the seat of the brain that enabled humanity to become one of the most successful species on the planet (and which also is very vulnerable at birth) was arguably a more urgent issue (axillary hair in the underarms and groin were also retained as signs of sexual maturity). Sometime during the gradual process by which Homo erectus began a transition from furry skin to the naked skin expressed by Homo sapiens, hair texture putatively gradually changed from straight hair[citation needed] (the condition of most mammals, including humanity's closest cousins—chimpanzees) to Afro-textured hair or 'kinky' (i.e. tightly coiled). This argument assumes that curly hair better impedes the passage of UV light into the body relative to straight hair (thus curly or coiled hair would be particularly advantageous for light-skinned hominids living at the equator).
It is substantiated by Iyengar's (1998) findings that UV light can enter into straight human hair roots (and thus into the body through the skin) via the hair shaft. Specifically, the results of that study suggest that this phenomenon resembles the passage of light through fiber optic tubes (which do not function as effectively when kinked or sharply curved or coiled). In this sense, when hominids (i.e. Homo Erectus) were gradually losing their straight body hair and thereby exposing the initially pale skin underneath their fur to the sun, straight hair would have been an adaptive liability. By inverse logic, later, as humans traveled farther from Africa and/or the equator, straight hair may have (initially) evolved to aid the entry of UV light into the body during the transition from dark, UV-protected skin to paler skin.
Some[who?] conversely believe that tightly coiled hair that grows into a typical Afro-like formation would have greatly reduced the ability of the head and brain to cool because although African people's hair is much less dense than its European counterpart's, in the intense sun the effective 'woolly hat' that such hair produced would have been a disadvantage. However, such anthropologists as Nina Jablonski oppositely argue about this hair texture. Specifically, Jablonski's assertions[49] suggest that the adjective "woolly" in reference to Afro-hair is a misnomer in connoting the high heat insulation derivable from the true wool of sheep. Instead, the relatively sparse density of Afro-hair, combined with its springy coils actually results in an airy, almost sponge-like structure that in turn, Jablonski argues,[49] more likely facilitates an increase in the circulation of cool air onto the scalp. Further, wet Afro-hair does not stick to the neck and scalp unless totally drenched and instead tends to retain its basic springy puffiness because it less easily responds to moisture and sweat than straight hair does. In this sense, the trait may enhance comfort levels in intense equatorial climates more than straight hair (which, on the other hand, tends to naturally fall over the ears and neck to a degree that provides slightly enhanced comfort levels in cold climates relative to tightly coiled hair).
Furthermore, some[who?] interpret the ideas of Charles Darwin as suggesting that some traits, such as hair texture, were so arbitrary to human survival that the role natural selection played was trivial. Hence, they argue in favor of his suggestion that sexual selection may be responsible for such traits. However, inclinations towards deeming hair texture "adaptively trivial" may root in certain cultural value judgments more than objective logic. In this sense the possibility that hair texture may have played an adaptively significant role cannot be completely eliminated from consideration. In fact, while the sexual selection hypothesis cannot be ruled out, the asymmetrical distribution of this trait vouches for environmental influence. Specifically, if hair texture were simply the result of adaptively arbitrary human aesthetic preferences, one would expect that the global distribution of the various hair textures would be fairly random. Instead, the distribution of Afro-hair is strongly skewed toward the equator.
Further, it is notable that the most pervasive expression of this hair texture can be found in sub-Saharan Africa; a region of the world that abundant genetic and paleo-anthropological evidence suggests, was the relatively recent (≈200,000-year-old) point of origin for modern humanity. In fact, although genetic findings (Tishkoff, 2009) suggest that sub-Saharan Africans are the most genetically diverse continental group on Earth, Afro-textured hair approaches ubiquity in this region; this points to a strong, long-term selective pressure that, in stark contrast to most other regions of the genomes of sub-Saharan groups, left little room for genetic variation at the determining loci. Such a pattern, again, does not seem to support human sexual aesthetics as being the sole or primary cause of this distribution.
Straight black hair
The EDAR locus
A group of studies have recently shown that genetic patterns at the EDAR locus, a region of the modern human genome that contributes to hair texture variation among most individuals of East Asian descent, support the hypothesis that (East Asian) straight hair likely developed in this branch of the modern human lineage subsequent to the original expression of tightly coiled natural afro-hair.[53][54][55] Specifically, the relevant findings indicate that the EDAR mutation coding for the predominant East Asian 'coarse' or thick, straight hair texture arose within the past ≈65,000 years, which is a time frame that covers from the earliest of the 'Out of Africa' migrations up to now.
See also: Hair diseases
Ringworm is a fungal disease that targets hairy skin.[56]
Premature greying of hair is another condition that results in greying before the age of 20 years in Whites, before 25 years in Asians, and before 30 years in Africans.[57]
Main article: Hair care
Hair care involves the hygiene and cosmetology of hair including hair on the scalp, facial hair (beard and moustache), pubic hair and other body hair. Hair care routines differ according to an individual's culture and the physical characteristics of one's hair. Hair may be colored, trimmed, shaved, plucked, or otherwise removed with treatments such as waxing, sugaring, and threading.
Removal practices
Depilation is the removal of hair from the surface of the skin; this can be achieved through methods such as shaving. Epilation is the removal of the entire hair strand, including the part of the hair that has not yet left the follicle. A popular way to epilate hair is through waxing.
Many razors have multiple blades purportedly to ensure a close shave. While shaving initially will leave skin feeling smooth and hair free, new hair growth can appear a few hours after hair removal.
Shaving is accomplished with bladed instruments, such as razors; the blade is brought close to the skin and stroked over the hair in the desired area to cut the terminal hairs and leave the skin feeling smooth. Depending upon the rate of growth, one can begin to feel the hair growing back within hours of shaving; this is especially evident in men who develop a five o'clock shadow after having shaved their faces. This new growth is called stubble. Stubble typically appears to grow back thicker because the shaved hairs are blunted instead of tapered off at the end, although the hair never actually grows back thicker.
Waxing involves using a sticky wax and strip of paper or cloth to pull hair from the root. Waxing is the ideal hair removal technique to keep an area hair-free for long periods of time, it can take three to five weeks for waxed hair to begin to resurface again. Hair in areas that have been waxed consistently is known to grow back finer and thinner, especially compared to hair that has been shaved with a razor.
Laser removal
Main article: Laser hair removal
Laser hair removal is a cosmetic method where a small laser beam pulses selective heat on dark target matter in the area that causes hair growth without harming the skin tissue; this process is repeated several times over the course of many months to a couple of years with hair regrowing less frequently until it finally stops; this is used as a more permanent solution to waxing or shaving. Laser removal is practiced in many clinics along with many at-home products.
Cutting and trimming
See also: Ponytail
Because the hair on one's head is normally longer than other types of body hair, it is cut with scissors or clippers. People with longer hair will most often use scissors to cut their hair, whereas shorter hair is maintained using a trimmer. Depending on the desired length and overall health of the hair, periods without cutting or trimming the hair can vary.
Cut hair may be used in wigs. Global imports of hair in 2010 was worth $US 1.24 billion.[58]
See also: Hairstyle
Hair has great social significance for human beings.[59] [60] It can grow on most external areas of the human body, except on the palms of the hands and the soles of the feet (among other areas). Hair is most noticeable on most people in a small number of areas, which are also the ones that are most commonly trimmed, plucked, or shaved; these include the face, ears, head, eyebrows, legs, and armpits, as well as the pubic region. The highly visible differences between male and female body and facial hair are a notable secondary sex characteristic.
The world's longest documented hair belongs to Xie Qiuping (China), at 5.627 m (18 ft 5.54 in) when measured on 8 May 2004. She has been growing her hair since 1973, from the age of 13.[61]
Indication of status
Healthy hair indicates health and youth (important in evolutionary biology). Hair color and texture can be a sign of ethnic ancestry. Facial hair is a sign of puberty in men. White hair is a sign of age or genetics, which may be concealed with hair dye (not easily for some), although many prefer to assume it (especially if it is a poliosis characteristic of the person since childhood). Male pattern baldness is a sign of age, which may be concealed with a toupee, hats, or religious and cultural adornments. Although drugs and medical procedures exist for the treatment of baldness, many balding men simply shave their heads. In early modern China, the queue was a male hairstyle worn by the Manchus from central Manchuria and the Han Chinese during the Qing dynasty; hair on the front of the head was shaved off above the temples every ten days, mimicking male-pattern baldness, and the rest of the hair braided into a long pigtail.
Hairstyle may be an indicator of group membership. During the English Civil War, the followers of Oliver Cromwell decided to crop their hair close to their head, as an act of defiance to the curls and ringlets of the king's men;[62] this led to the Parliamentary faction being nicknamed Roundheads. Recent isotopic analysis of hair is helping to shed further light on sociocultural interaction, giving information on food procurement and consumption in the 19th century .[63] Having bobbed hair was popular among the flappers in the 1920s as a sign of rebellion against traditional roles for women. Female art students known as the "cropheads" also adopted the style, notably at the Slade School in London, England. Regional variations in hirsutism cause practices regarding hair on the arms and legs to differ; some religious groups may follow certain rules regarding hair as part of religious observance. The rules often differ for men and women.
Many subcultures have hairstyles which may indicate an unofficial membership. Many hippies, metalheads and Indian sadhus have long hair, as well many older indie kids. Many punks wear a hairstyle known as a mohawk or other spiked and dyed hairstyles; skinheads have short-cropped or completely shaved heads. Long stylized bangs were very common for emos, scene kids and younger indie kids in the 2000s and early 2010s, among people of both genders.
Heads were shaved in concentration camps, and head-shaving has been used as punishment, especially for women with long hair; the shaven head is common in military haircuts, while Western monks are known for the tonsure. By contrast, among some Indian holy men, the hair is worn extremely long.[citation needed]
In the time of Confucius (5th century BCE), the Chinese grew out their hair and often tied it, as a symbol of filial piety.
Regular hairdressing in some cultures is considered a sign of wealth or status; the dreadlocks of the Rastafari movement were despised early in the movement's history. In some cultures, having one's hair cut can symbolize a liberation from one's past, usually after a trying time in one's life. Cutting the hair also may be a sign of mourning.
Tightly coiled hair in its natural state may be worn in an Afro; this hairstyle was once worn among African Americans as a symbol of racial pride. Given that the coiled texture is the natural state of some African Americans' hair, or perceived as being more "African", this simple style is now often seen as a sign of self-acceptance and an affirmation that the beauty norms of the (eurocentric) dominant culture are not absolute, it is important to note that African Americans as a whole have a variety of hair textures, as they are not an ethnically homogeneous group, but an ad-hoc of different racial admixtures.
The film Easy Rider (1969) includes the assumption that the two main characters could have their long hairs forcibly shaved with a rusty razor when jailed, symbolizing the intolerance of some conservative groups toward members of the counterculture. At the conclusion of the Oz obscenity trials in the UK in 1971, the defendants had their heads shaved by the police, causing public outcry. During the appeal trial, they appeared in the dock wearing wigs.[64] A case where a 14-year-old student was expelled from school in Brazil in the mid-2000s, allegedly because of his fauxhawk haircut, sparked national debate and legal action resulting in compensation.[65][66]
Women's hair may be hidden using headscarves, a common part of the hijab in Islam and a symbol of modesty required for certain religious rituals in Eastern Orthodoxy. Russian Orthodox Church requires all married women to wear headscarves inside the church; this tradition is often extended to all women, regardless of marital status. Orthodox Judaism also commands the use of scarves and other head coverings for married women for modesty reasons. Certain Hindu sects also wear head scarves for religious reasons. Sikhs have an obligation not to cut hair (a Sikh cutting hair becomes 'apostate' which means fallen from religion)[67] and men keep it tied in a bun on the head, which is then covered appropriately using a turban. Multiple religions, both ancient and contemporary, require or advise one to allow their hair to become dreadlocks, though people also wear them for fashion. For men, Islam, Orthodox Judaism, Orthodox Christianity, Roman Catholicism, and other religious groups have at various times recommended or required the covering of the head and sections of the hair of men, and some have dictates relating to the cutting of men's facial and head hair; some Christian sects throughout history and up to modern times have also religiously proscribed the cutting of women's hair. For some Sunni madhabs, the donning of a kufi or topi is a form of sunnah.[68]
Chaetophobia – the fear of hair
Hair analysis (alternative medicine)
Hypertrichosis – the state of having an excess of hair on the head or body
Hypotrichosis – the state of having a less than normal amount of hair on the head or body
Lanugo
Seta – hair-like structures in insects
Trichotillomania – hair pulling
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Wikimedia Commons has media related to Hair.
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Look up hair in Wiktionary, the free dictionary.
How to measure the diameter of your own hair using a laser pointer
Instant insight outlining the chemistry of hair from the Royal Society of Chemistry
The dictionary definition of hairsbreadth at Wiktionary
PUIU, TIBI (23 August 2018). "How fast hair grows, and other hairy science". ZME Science. Retrieved 30 August 2018.
List of hairstyles / facial hairstyles
Androgenic
Vellus
Unibrow
Pubic
Afro puffs
Asymmetric cut
Big hair
Bob cut
Bowl cut
Braid or Plait
Brush cut
Bun (odango)
Businessman cut
Butch cut
Buzz cut
Caesar cut
Chonmage
Chupryna
Conk
Croydon facelift
Curtained hair
Dido flip
Digital perm
Duck's ass
Feathered hair
Finger wave
Flattop
Fontange
Frosted tips
Hair crimping
Harvard clip
High and tight
Hime cut
Historical Christian hairstyles
Hi-top fade
Induction cut
Jewfro
Jheri curl
Kiss curl
Liberty spikes
Lob cut
Marcelling
Mod cut
Polish halfshaven head
Punch perm
Professional cut
Quiff
Razor cut
Regular haircut
Ringlets
Shag (shaggy hair)
Shape-Up
Short brush cut
Spiky hair
Standard haircut
Surfer hair
Taper cut
Temple Fade
Widow's peak
Chinstrap
Designer stubble
Shenandoah (chin curtain)
Soul patch
Van Dyke
plucking
totalis
Frictional alopecia
Male-pattern hair loss
Trichophilia
Pogonophobia
Haircare techniques
Backcombing
Shampoo and set
My Nappy Roots: A Journey Through Black Hair-itage (2008)
Good Hair (2009)
Afro-textured hair (kinky hair)
Beard and haircut laws by country
Bearded lady
Barber (pole)
Eponymous hairstyle
Good hair
Hair fetishism (pubic)
Hair follicle
Skin and related structures
Stratum corneum
Stratum lucidum
Stratum granulosum
Stratum spinosum
Stratum basale
Basal keratinocyte
Lamina lucida
Lamina densa
Dermal papillae
Reticular
Subcutaneous tissue
Panniculus/Pannus (Panniculus adiposus
Panniculus carnosus)
Membranous layer
Loose connective tissue
Superficial fascia
Adnexa
Skin glands
Sweat glands: Apocrine sweat gland
Eccrine sweat gland
Root sheath
Outer root sheath
Inner root sheath
Henle's layer
Huxley's layer
Hair shaft
Bulb with matrix cells
Arrector pili muscle
Pilosebaceous unit
Hair sebaceous gland
Nail matrix
Nail plate
Lunula
Eponychium
Paronychium
Hyponychium
(Hominins)
Orrorin
Sahelanthropus
Last common ancestors
Chimpanzee–human
Gorilla–human
Orangutan–human
Gibbon–human
Australopithecines
Ardipithecus
Kenyanthropus
A. afarensis
A. africanus
A. anamensis
A. bahrelghazali
A. deyiremeda
A. garhi
A. sediba
Paranthropus
P. aethiopicus
P. boisei
P. robustus
Humans and
proto-humans
(Homo)
H. habilis
H. floresiensis
H. gautengensis
H. rudolfensis
H. tsaichangensis
H. ergaster
H. e. erectus
H. e. georgicus
H. e. lantianensis
H. e. nankinensis
H. e. palaeojavanicus
H. e. pekinensis
H. e. soloensis
H. e. tautavelensis
H. e. yuanmouensis
Archaic humans
H. antecessor
H. cepranensis
H. denisova
H. heidelbergensis
H. helmei
H. luzonensis
H. naledi
H. neanderthalensis
H. rhodesiensis
Modern humans
H. s. sapiens (archaic homo sapiens, anatomically modern humans)
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H. s. idaltu
Manot people
Red Deer Cave people
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General models
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Keratin is one of a family of fibrous structural proteins. It is the key structural material making up hair, horns, claws and the outer layer of human skin. Keratin is the protein that protects epithelial cells from damage or stress. Keratin is insoluble in water and organic solvents. Keratin monomers assemble into bundles to form intermediate filaments, which are tough and form strong unmineralized epidermal appendages found in reptiles, birds and mammals; the only other biological matter known to approximate the toughness of keratinized tissue is chitin. Keratin filaments are abundant in keratinocytes in the cornified layer of the epidermis. In addition, keratin filaments are present in epithelial cells in general. For example, mouse thymic epithelial cells are known to react with antibodies for keratin 5, keratin 8, keratin 14; these antibodies are used as fluorescent markers to distinguish subsets of TECs in genetic studies of the thymus. The α-keratins are found in all vertebrates, they form the hair, stratum corneum, nails and hooves of mammals and the hagfish slime threads.
The harder β-keratins are found only in the sauropsids, all living reptiles and birds. They are found in the nails and claws of reptiles, some reptile shells, in the feathers and claws of birds. Additionally, the baleen plates of filter-feeding whales are made of keratin. Keratins are polymers of type I and type II intermediate filaments, which have only been found in the genomes of chordates. Nematodes and many other non-chordate animals seem to only have type VI intermediate filaments, which have a long rod domain; the human genome encodes 54 functional keratin genes which are located in two clusters on chromosomes 12 and 17. This suggests; the keratins include the following proteins of which KRT23, KRT24, KRT25, KRT26, KRT27, KRT28, KRT31, KRT32, KRT33A, KRT33B, KRT34, KRT35, KRT36, KRT37, KRT38, KRT39, KRT40, KRT71, KRT72, KRT73, KRT74, KRT75, KRT76, KRT77, KRT78, KRT79, KRT8, KRT80, KRT81, KRT82, KRT83, KRT84, KRT85 and KRT86 have been used to describe keratins past 20. The first sequences of keratins were determined by Fuchs.
These sequences revealed that there are two distinct but homologous keratin families which were named as Type I keratin and Type II keratins. By analysis of the primary structures of these keratins and other intermediate filament proteins and Fuchs suggested a model that keratins and intermediate filament proteins contain a central ~310 residue domain with four segments in α-helical conformation that are separated by three short linker segments predicted to be in beta-turn conformation; this model has been confirmed by the determination of the crystal structure of a helical domain of keratins. Fibrous keratin molecules supercoil to form a stable, left-handed superhelical motif to multimerise, forming filaments consisting of multiple copies of the keratin monomer; the major force that keeps the coiled-coil structure is hydrophobic interactions between apolar residues along the keratins helical segments. Limited interior space is the reason why the triple helix of the structural protein collagen, found in skin and bone has a high percentage of glycine.
The connective tissue protein elastin has a high percentage of both glycine and alanine. Silk fibroin, considered a β-keratin, can have these two as 75–80% of the total, with 10–15% serine, with the rest having bulky side groups; the chains are antiparallel, with an alternating C → N orientation. A preponderance of amino acids with small, nonreactive side groups is characteristic for structural proteins, for which H-bonded close packing is more important than chemical specificity. In addition to intra- and intermolecular hydrogen bonds, the distinguishing feature of keratins is the presence of large amounts of the sulfur-containing amino acid cysteine, required for the disulfide bridges that confer additional strength and rigidity by permanent, thermally stable crosslinking—in much the same way that non-protein sulfur bridges stabilize vulcanized rubber. Human hair is 14% cysteine; the pungent smells of burning hair and skin are due to the volatile sulfur compounds formed. Extensive disulfide bonding contributes to the insolubility of keratins, except in a small number of solvents such as dissociating or reducing agents.
The more flexible and elastic keratins of hair have fewer interchain disulfide bridges than the keratins in mammalian fingernails and claws, which are harder and more like their analogs in other vertebrate classes. Hair and other α-keratins consist of α-helically coiled single protein strands, which are further twisted into superhelical ropes that may be further coiled; the β-keratins of reptiles and birds have β-pleated sheets twisted together stabilized and hardened by disulfide bridges. It has been proposed that keratins can be divided into'hard' and'soft' forms, or'cytokeratins' and'other keratins'; that model is now understood to be correct. A new nuclear addition in 2006 to describe keratins takes this into account. Keratin filaments are intermediate filaments. Like all intermediate filaments, keratin proteins form filamentous polymers in a series of assembly steps beginning with dimerization.
Melanin is a broad term for a group of natural pigments found in most organisms. Melanin is produced through a multistage chemical process known as melanogenesis, where the oxidation of the amino acid tyrosine, is followed by polymerization; the melanin pigments are produced in a specialized group of cells known as melanocytes. There are three basic types of melanin: eumelanin and neuromelanin; the most common type is eumelanin, of which there are two types -- black eumelanin. Pheomelanin is a cysteine-derivative that contains polybenzothiazine portions that are responsible for the color of red hair, among other pigmentation. Neuromelanin is found in the brain. Research has been undertaken to investigate its efficacy in treating neurodegenerative disorders such as Parkinson's. In the human skin, melanogenesis is initiated by exposure to UV radiation, causing the skin to darken. Melanin is an effective absorbent of light; because of this property, melanin is thought to protect skin cells from UVB radiation damage, reducing the risk of folate depletion and dermal degradation, it is considered that exposure to UV radiation is associated with increased risk of malignant melanoma, a cancer of melanocytes.
Studies have shown a lower incidence for skin cancer in individuals with more concentrated melanin, i.e. darker skin tone. However. In humans, melanin is the primary determinant of skin color, it is found in hair, the pigmented tissue underlying the iris of the eye, the stria vascularis of the inner ear. In the brain, tissues with melanin include the medulla and pigment-bearing neurons within areas of the brainstem, such as the locus coeruleus and the substantia nigra, it occurs in the zona reticularis of the adrenal gland. The melanin in the skin is produced by melanocytes, which are found in the basal layer of the epidermis. Although, in general, human beings possess a similar concentration of melanocytes in their skin, the melanocytes in some individuals and ethnic groups produce variable amounts of melanin; some humans have little or no melanin synthesis in their bodies, a condition known as albinism. Because melanin is an aggregate of smaller component molecules, there are many different types of melanin with different proportions and bonding patterns of these component molecules.
Both pheomelanin and eumelanin are found in human skin and hair, but eumelanin is the most abundant melanin in humans, as well as the form most to be deficient in albinism. Eumelanin polymers have long been thought to comprise numerous cross-linked 5,6-dihydroxyindole and 5,6-dihydroxyindole-2-carboxylic acid polymers. Pheomelanins impart a pink depending upon the concentration. Pheomelanins are concentrated in the lips, glans of the penis, vagina; when a small amount of brown eumelanin in hair, which would otherwise cause blond hair, is mixed with red pheomelanin, the result is strawberry blonde. Pheomelanin is present in the skin, redheads often have a more pinkish hue to their skin as well. In chemical terms, pheomelanins differ from eumelanins in that the oligomer structure incorporates benzothiazine and benzothiazole units that are produced, instead of DHI and DHICA, when the amino acid L-cysteine is present. Trichochromes are pigments produced from the same metabolic pathway as the eumelanins and pheomelanins, but unlike those molecules they have low molecular weight.
They occur in some red human hair. Neuromelanin is a dark insoluble polymer pigment produced in specific populations of catecholaminergic neurons in the brain. Humans have the largest amount of NM, present in lesser amounts in other primates, absent in many other species. However, the biological function remains unknown, although human NM has been shown to efficiently bind transition metals such as iron, as well as other toxic molecules. Therefore, it may play crucial roles in the related Parkinson's disease. Melanins have diverse roles and functions in various organisms. A form of melanin makes up the ink used by many cephalopods as a defense mechanism against predators. Melanins protect microorganisms, such as bacteria and fungi, against stresses that involve cell damage such as UV radiation from the sun and reactive oxygen species. Melanin protects against damage from high temperatures, chemical stresses, biochemical threats. Therefore, in many pathogenic microbes melanins appear to play important roles in virulence and pathogenicity by protecting the microbe against immune responses of its host.
In invertebrates, a major aspect of the innate immune defense system against invading pathogens involves melanin. Within minutes after infection, the microbe is encapsulated within melanin, the generation of free radical byproducts during the formation of this capsule is thought to aid in killing them; some types of fungi, called radiotrophic fungi, appear to be able to use melanin as a photosynthetic pigment that enables them to capture gamma rays and harness this energy for growth. The darker feathers of birds owe their color to melanin and are less degraded by bacteria than unpigmented ones or those containing carotenoid pigments. Feathers that contain melanin are 39% more resistant to abrasion than those that do not because melanin granules help fill the space between th
Henle's layer is the third and the outermost layer of the inner root sheath of the hair follicle, consisting of a single layer of cubical cells with clear flattened nuclei. It is named after German physician and anatomist Friedrich Gustav Jakob Henle; this article incorporates text in the public domain from page 1068 of the 20th edition of Gray's Anatomy synd/649 at Who Named It
Organ system
An organ system is a group of organs that work together as a biological system to perform one or more functions. Each organ system does a particular job in the body, is made up of certain tissues; these specific systems are studied in anatomy. They are present in many types of animals. Respiratory system: the organs used for breathing, the pharynx, bronchi and diaphragm. Digestive system: digestion and processing food with salivary glands, stomach, gallbladder, intestines and anus. Cardiovascular system: and channeling blood to and from the body and lungs with heart and blood vessels. Urinary system: kidneys, ureters and urethra involved in fluid balance, electrolyte balance and excretion of urine. Integumentary system: skin, hair and nails. Skeletally system: structural support and protection with bones, cartilage and tendons. Endocrine system: communication within the body using hormones made by endocrine glands such as the hypothalamus, pituitary gland, pineal gland, thyroid and adrenal glands.
Lymphatic system: the transfer of lymph between tissues and the blood stream. Includes the functions of immune responses and the development of antibodies. Our bodies consist of a number of biological systems that carry out specific functions necessary for everyday living; the job of the circulatory system is to move blood, oxygen, carbon dioxide, hormones, around the body. It consists of the heart, blood vessels and veins. Immune system: protects the organism from foreign bodies. Nervous system: collecting and processing information with brain, spinal cord, peripheral nervous system and sense organs. Sensory systems: visual system, auditory system, olfactory system, gustatory system, somatosensory system, vestibular system. Muscular system: allows for manipulation of the environment, provides locomotion, maintains posture, produces heat. Includes skeletal muscles, smooth muscles and cardiac muscle. Reproductive system: the sex organs, such as ovaries, fallopian tubes, vagina, mammary glands, testes, vas deferens, seminal vesicles and prostate
Blond or fair hair is a hair color characterized by low levels of the dark pigment eumelanin. The resultant visible hue always has some yellowish color; the color can be from the pale blond to reddish "strawberry" blond or golden-brownish blond colors. Because hair color tends to darken with age, natural blond hair is very rare in adulthood. Naturally-occurring blond hair is found in populations of northern European descent and is believed to have evolved to enable more efficient synthesis of vitamin D, due to northern Europe's lower levels of sunlight. Blond hair has developed in other populations, although it is not as common, can be found among natives of the Solomon Islands and Fiji, among the Berbers of North Africa, among some Asians. In Western culture, blond hair has long been associated with female beauty. Aphrodite, the Greek goddess of love and beauty, was reputed to have blond hair. In ancient Greece and Rome, blond hair was associated with prostitutes, who dyed their hair using saffron dyes in order to attract customers.
The Greeks stereotyped Thracians and slaves as blond and the Romans associated blondness with the Celts and the Germans to the north. In western Europe during the Middle Ages, blond hair was idealized as the paragon of female beauty; the Norse goddess Sif and the medieval heroine Iseult were both portrayed as blond and, in medieval artwork, Mary Magdalene, the Virgin Mary are shown with blond hair. In the late nineteenth and early twentieth century, scientific racists categorized blond hair and blue eyes as characteristics of the supreme Nordic race. In contemporary western culture, blonde women are negatively stereotyped as sexually attractive, but unintelligent; the word "blond" is first documented in English in 1481 and derives from Old French blund, meaning "a colour midway between golden and light chestnut". It eclipsed the native term "fair", of same meaning, from Old English fæġer, causing "fair" to become a general term for "light complexioned"; this earlier use of "fair" survives in the proper name Fairfax, from Old English fæġer-feahs meaning "blond hair".
The word "blond" has two possible origins. Some linguists say it comes from Medieval Latin blundus, meaning "yellow", from Old Frankish blund which would relate it to Old English blonden-feax meaning "grey-haired", from blondan/blandan meaning "to mix". Old English beblonden meant "dyed", as ancient Germanic warriors were noted for dyeing their hair. However, linguists who favor a Latin origin for the word say that Medieval Latin blundus was a vulgar pronunciation of Latin flavus meaning "yellow". Most authorities French, attest to the Frankish origin; the word was reintroduced into English in the 17th century from French, was for some time considered French. "Blond", with its continued gender-varied usage, is one of few adjectives in written English to retain separate lexical genders. The two forms, are pronounced identically. American Heritage's Book of English Usage propounds that, insofar as "a blonde" can be used to describe a woman but not a man, said to possess blond hair, the term is an example of a "sexist stereotype women are defined by their physical characteristics."
The Oxford English Dictionary records that the phrase "big blond beast" was used in the 20th century to refer to men "of the Nordic type". The OED records that blond as an adjective is used with reference to women, in which case it is to be spelt "blonde", citing three Victorian usages of the term; the masculine version is used in the plural, in "blonds of the European race", in a citation from 1833 Penny cyclopedia, which distinguishes genuine blondness as a Caucasian feature distinct from albinism. By the early 1990s, "blonde moment" or being a "dumb blonde" had come into common parlance to mean "an instance of a person, esp. A woman... being foolish or scatter-brained." Another hair color word of French origin, functions in the same way in orthodox English. The OED gives "brunet" as meaning "dark-complexioned" or a "dark-complexioned person", citing a comparative usage of brunet and blond to Thomas Henry Huxley in saying, "The present contrast of blonds and brunets existed among them." "Brunette" can be used, like "blonde", to describe a mixed-gender populace.
The OED quotes Grant Allen, "The nation which resulted... being sometimes blonde, sometimes brunette.""Blond" and "blonde" are occasionally used to refer to objects that have a color reminiscent of fair hair. For example, the OED records its use in 19th-century poetic diction to describe flowers, "a variety of clay ironstone of the coal measures", "the colour of raw silk", a breed of ray, lager beer, pale wood. Various subcategories of blond hair have been defined to describe the different shades and sources of the hair color more accurately. Common examples include the following: ash-blond: grayish blond. Bleached blond, bottle blond, or peroxide blond: terms used to refer to artificially colored blond hair. Blond/flaxen: when distinguished from other varieties, "blond" by itself refers to a light but not whitish blond, with no traces of red, gold, or brown. Dirty blond or dishwater blond: dark blond with flecks of golden blond and brown. Golden blond: a darker to rich, golden-yellow blond (found in Northeastern Europe, i.e. Russia
A pigment is a material that changes the color of reflected or transmitted light as the result of wavelength-selective absorption. This physical process differs from fluorescence and other forms of luminescence, in which a material emits light. Most materials selectively absorb certain wavelengths of light. Materials that humans have chosen and developed for use as pigments have special properties that make them useful for coloring other materials. A pigment must have a high tinting strength relative to the materials colors, it must be stable in solid form at ambient temperatures. For industrial applications, as well as in the arts and stability are desirable properties. Pigments that are not permanent are called fugitive. Fugitive pigments fade over time, or with exposure to light, while some blacken. Pigments are used for coloring paint, plastic, cosmetics and other materials. Most pigments used in manufacturing and the visual arts are dry colorants ground into a fine powder. For use in paint, this powder is added to a binder, a neutral or colorless material that suspends the pigment and gives the paint its adhesion.
A distinction is made between a pigment, insoluble in its vehicle, a dye, which either is itself a liquid or is soluble in its vehicle. A colorant can act as either a dye depending on the vehicle involved. In some cases, a pigment can be manufactured from a dye by precipitating a soluble dye with a metallic salt; the resulting pigment is called a lake pigment. The term biological pigment is used for all colored substances independent of their solubility. In 2006, around 7.4 million tons of inorganic and special pigments were marketed worldwide. Asia has the highest rate on a quantity basis followed by North America; the global demand on pigments was US$20.5 billion in 2009. Pigments appear colored because they selectively reflect and absorb certain wavelengths of visible light. White light is a equal mixture of the entire spectrum of visible light with a wavelength in a range from about 375 or 400 nanometers to about 760 or 780 nm; when this light encounters a pigment, parts of the spectrum are absorbed by the pigment.
Organic pigments such as diazo or phthalocyanine compounds feature conjugated systems of double bonds. Some inorganic pigments, such as vermilion or cadmium yellow, absorb light by transferring an electron from the negative ion to the positive ion; the other wavelengths or parts of the spectrum are scattered. The new reflected. Pigments, unlike fluorescent or phosphorescent substances, can only subtract wavelengths from the source light, never add new ones; the appearance of pigments is intimately connected to the color of the source light. Sunlight has a high color temperature and a uniform spectrum and is considered a standard for white light, while artificial light sources tend to have strong peaks in parts of their spectra. Viewed under different lights, pigments will appear different colors. Color spaces used to represent colors. Lab color measurements, unless otherwise noted, assume that the measurement was taken under a D65 light source, or "Daylight 6500 K", the color temperature of sunlight.
Other properties of a color, such as its saturation or lightness, may be determined by the other substances that accompany pigments. Binders and fillers added to pure pigment chemicals have their own reflection and absorption patterns, which can affect the final spectrum. For example, in pigment/binder mixtures, individual rays of light may not encounter pigment molecules and may be reflected unchanged; these stray rays of source light make. Pure pigment allows little white light to escape, producing a saturated color, while a small quantity of pigment mixed with a lot of white binder will appear unsaturated and pale due to incident white light escaping unchanged. Occurring pigments such as ochres and iron oxides have been used as colorants since prehistoric times. Archaeologists have uncovered evidence that early humans used paint for aesthetic purposes such as body decoration. Pigments and paint grinding equipment believed to be between 350,000 and 400,000 years old have been reported in a cave at Twin Rivers, near Lusaka, Zambia.
Before the Industrial Revolution, the range of color available for art and decorative uses was technologically limited. Most of the pigments in use were pigments of biological origin. Pigments from unusual sources such as botanical materials, animal waste and mollusks were harvested and traded over long distances; some colors were impossible to obtain, given the range of pigments that were available. Blue and purple came to be associated with royalty because of their rarity. Biological pigments were difficult to acquire, the details of their production were kept secret by the manufacturers. Tyrian Purple is a pigment made from the mucus of one of several species of Murex snail. Production of Tyrian Purple for use as a fabric dye began as early as 1200 BCE by the Phoenicians, was continued by the Greeks and Romans until 1453 CE, with the fall of Constantinople; the pigment was expensive and complex to produce, items colored with it became associated with power and wealth. Greek historian Theopompus, writing in the 4th century BCE, reported that "purple for dyes fetched its weight in silver at Colophon."Mineral pigments were traded over long distances.
The only w
A biomaterial is any substance, engineered to interact with biological systems for a medical purpose - either a therapeutic or a diagnostic one. As a science, biomaterials is about fifty years old; the study of biomaterials is called biomaterials science or biomaterials engineering. It has experienced steady and strong growth over its history, with many companies investing large amounts of money into the development of new products. Biomaterials science encompasses elements of medicine, chemistry, tissue engineering and materials science. Note that a biomaterial is different from a biological material, such as bone, produced by a biological system. Additionally, care should be exercised in defining a biomaterial as biocompatible, since it is application-specific. A biomaterial, biocompatible or suitable for one application may not be biocompatible in another. Biomaterials can be derived either from nature or synthesized in the laboratory using a variety of chemical approaches utilizing metallic components, ceramics or composite materials.
They are used and/or adapted for a medical application, thus comprises whole or part of a living structure or biomedical device which performs, augments, or replaces a natural function. Such functions may be passive, like being used for a heart valve, or may be bioactive with a more interactive functionality such as hydroxy-apatite coated hip implants. Biomaterials are used every day in dental applications and drug delivery. For example, a construct with impregnated pharmaceutical products can be placed into the body, which permits the prolonged release of a drug over an extended period of time. A biomaterial may be an autograft, allograft or xenograft used as a transplant material; the ability of an engineered biomaterial to induce a physiological response, supportive of the biomaterial's function and performance is known as bioactivity. Most in bioactive glasses and bioactive ceramics this term refers to the ability of implanted materials to bond well with surrounding tissue in either osseoconductive or osseoproductive roles.
Bone implant materials are designed to promote bone growth while dissolving into surrounding body fluid. Thus for many biomaterials good biocompatibility along with good strength and dissolution rates are desirable. Bioactivity of biomateirals is gauged by the surface biomineralisation in which a native layer of hydroxyapatite is formed at the surface. Self-assembly is the most common term in use in the modern scientific community to describe the spontaneous aggregation of particles without the influence of any external forces. Large groups of such particles are known to assemble themselves into thermodynamically stable, structurally well-defined arrays, quite reminiscent of one of the 7 crystal systems found in metallurgy and mineralogy; the fundamental difference in equilibrium structure is in the spatial scale of the unit cell in each particular case. Molecular self-assembly is found in biological systems and provides the basis of a wide variety of complex biological structures; this includes an emerging class of mechanically superior biomaterials based on microstructural features and designs found in nature.
Thus, self-assembly is emerging as a new strategy in chemical synthesis and nanotechnology. Molecular crystals, liquid crystals, micelles, phase-separated polymers, thin films and self-assembled monolayers all represent examples of the types of ordered structures which are obtained using these techniques; the distinguishing feature of these methods is self-organization. Nearly all materials could be seen as hierarchically structured since the changes in spatial scale bring about different mechanisms of deformation and damage. However, in biological materials this hierarchical organization is inherent to the microstructure. One of the first examples of this, in the history of structural biology, is the early X-ray scattering work on the hierarchical structure of hair and wool by Astbury and Woods. In bone, for example, collagen is the building block of the organic matrix — a triple helix with diameter of 1.5 nm. These tropocollagen molecules are intercalated with the mineral phase forming fibrils that curl into helicoids of alternating directions.
These "osteons" are the basic building blocks of bones, with the volume fraction distribution between organic and mineral phase being about 60/40. In another level of complexity, the hydroxyapatite crystals are mineral platelets that have a diameter of 70–100 nm and thickness of 1 nm, they nucleate at the gaps between collagen fibrils. The hierarchy of abalone shell begins at the nanolevel, with an organic layer having a thickness of 20–30 nm; this layer proceeds with single crystals of aragonite consisting of "bricks" with dimensions of 0.5 and finishing with layers 0.3 mm. Crabs are arthropods whose carapace is made of a mineralized hard component and a softer organic component composed of chitin; the brittle component is arranged in a helical pattern. Each of these mineral 'rods' contains chitin–protein fibrils with 60 nm diameter; these fibrils are made of 3 nm diameter canals which link the exterior of the shell. Biomaterials are used in: Joint replacements Bone plates Intraocular lenses for eye surgery Bone cement Artificial ligaments and tendons Dental implants for tooth fixation Blood vessel prosth
Mammal [videos]
Mammals are vertebrate animals constituting the class Mammalia, and characterized by the presence of mammary glands which in females produce milk for feeding their young, a neocortex, fur or hair, and three middle ear bones. These …
Bovine kidney
A bonobo fishing for termites with a stick
Hairstyle [videos]
A hairstyle, hairdo, or haircut refers to the styling of hair, usually on the human scalp. Sometimes, this could also mean an editing of facial or body hair. The fashioning of hair can be considered an aspect of personal grooming, fashion, and cosmetics, although practical, cultural, and popular …
Elderly Chinese woman with elaborate hair style. John Thomson. China, 1869. The Wellcome Collection, London.
Traditional hairstyle of a Japanese bride.
The Venus of Willendorf with braided hair (or wearing a woven basket).
The Venus of Brassempouy
Human hair color [videos]
Hair color is the pigmentation of hair follicles due to two types of melanin: eumelanin and pheomelanin. Generally, if more eumelanin is present, the color of the hair is darker; if less eumelanin is present, the hair is lighter. Levels of melanin can vary over time causing a person's hair color to …
A variety of the human hair colors. From top left, clockwise: black, brown, blonde, white, red.
The same man at age 56, with fully-gray hair
A hairdresser colors a client's hair.
Image: Girl with long black hair (ponytail), rear view
Brown hair [videos]
Brown hair is the second most common human hair color, after black hair. It varies from light brown to almost black hair. It is characterized by higher levels of the dark pigment eumelanin and lower levels of the pale pigment pheomelanin. Its strands are thicker than those of fair hair but not as …
A person with brown hair
A close-up view of brown hair
Image: Girl in a Kabul orphanage, 01 07 2002
Image: Little girl with brown hair
Black hair [videos]
Black hair is the darkest and most common of all human hair colors globally, due to larger populations with this dominant trait. It is a dominant genetic trait, and it is found in people of all backgrounds and ethnicities. It has large amounts of eumelanin and is less dense than other hair colors …
Image: San tribesman new
Image: A boy with short black hair, rear view
Image: Rear view of a woman with shiny long black hair
Image: Chinese American girl
Red hair [videos]
Red hair occurs naturally in one to two percent of the human population, appearing with greater frequency among people of northern or western European ancestry and lesser frequency in other populations. It is most common in individuals homozygous for a …
Woman with red hair
Man with red hair and beard.
A Roman fresco depicting Bacchus with red hair, Boscoreale, c. 30 BC
Hades abducting Persephone, fresco in the small royal tomb at Vergina, Macedonia, Greece, c. 340 BC
Blond [videos]
Blond or fair hair is a hair color characterized by low levels of the dark pigment eumelanin. The resultant visible hue depends on various factors, but always has some yellowish color. The color can be from the very pale blond to reddish …
A man with blond hair and a blond beard
Blondes of different shades at WTMD's First Thursday series in Canton, Baltimore, Maryland, United States, in June 2014
Blonde girl from Vanuatu
Propaganda in Nazi Germany often featured people with blond hair and blue eyes, said to embody features of a "master race".
Pigment [videos]
A pigment is a material that changes the color of reflected or transmitted light as the result of wavelength-selective absorption. This physical process differs from fluorescence, phosphorescence, and other forms of luminescence, in which a material emits light. Most materials selectively absorb …
Natural ultramarine pigment in powdered form
Synthetic ultramarine pigment is chemically identical to natural ultramarine
Pigment Colours - Classification
Miracle of the Slave by Tintoretto (c. 1548). The son of a master dyer, Tintoretto used Carmine Red Lake pigment, derived from the cochineal insect, to achieve dramatic color effects.
Hair removal [videos]
Hair removal, also known as epilation or depilation, is the deliberate removal of body hair. — Hair typically grows all over the human body. Hair can become more visible during and after puberty and men tend to have thicker, more visible body hair than women. — Both men and women have visible hair on …
A woman's unshaven underarm...
...and a man's underarm that has been shaved
Body hair on an unusually hirsute male
Epidermis [videos]
The epidermis is the outermost of the three layers that make up the skin, the inner layers being the dermis and hypodermis. The epidermis layer provides a barrier to infection from environmental pathogens and regulates the amount of water released from the body into the atmosphere through …
Microscopic image of the epidermis, which constitutes the outer layer of skin, shown here by the white bar
Confocal image of the stratum granulosum
Image: Normal Epidermis and Dermis with Intradermal Nevus 10x
Anatomical terminology [videos]
Anatomical terminology is a form of scientific terminology used by anatomists, zoologists, and health professionals such as doctors. — Anatomical terminology uses many unique terms, suffixes, and prefixes deriving from Ancient Greek and Latin. These terms can be confusing to those unfamiliar with …
The biceps brachii flex the lower arm. The brachioradialis, in the forearm, and brachialis, located deep to the biceps in the upper arm, are both synergists that aid in this motion.
Image: Anatomical position
Vellus hair [videos]
Vellus hair is short, thin, slight-colored, and barely noticeable thin hair that develops on most of a person's body during childhood. Exceptions include the lips, the back of the ear, the palm of the hand, the sole of the foot, some external genital areas, the navel, and scar tissue. The density …
Vellus hay hair
Comparison of the vellus hair (left) to the terminal hair (right) in humans.
Human hair growth [videos]
The growth of human hair occurs everywhere on the body except for the soles of the feet, the lips, palms of the hands, some external genital areas, the navel, scar tissue, and, apart from eyelashes, the eyelids. Hair is a stratified squamous keratinized epithelium made of multi-layered flat cells …
Hair grows at different speeds and different lengths. Its composition causes different colors and textures, which influence how long the hair strands grow.
Marianne Ernst, a German "Long hair model".
Keratin [videos]
Keratin is one of a family of fibrous structural proteins. It is the key structural material making up hair, nails, horns, claws, hooves, and the outer layer of human skin. Keratin is also the protein that protects epithelial cells from damage or stress. Keratin is extremely insoluble in water …
Horns such as those of the impala are made up of keratin covering a core of live bone.
Microscopy of keratin filaments inside cells.
Melanin [videos]
Melanin is a broad term for a group of natural pigments found in most organisms. Melanin is produced through a multistage chemical process known as melanogenesis, where the oxidation of the amino acid tyrosine, is followed by polymerization. The …
Melanin pigment (light refracting granular material—center of image) in a pigmented melanoma.
Albinism occurs when melanocytes produce little melanin. This albino girl is from Papua New Guinea.
Arrector pili muscle [videos]
The arrector pili muscles are small muscles attached to hair follicles in mammals. Contraction of these muscles causes the hairs to stand on end, known colloquially as goose bumps. — Each arrector pili is composed of a bundle of smooth muscle fibres which attach to several follicles (a follicular …
Base of pilosebaceous unit: An arrector pili muscle can be seen as the pink-staining band of tissue at the bottom center and bottom left of image
Image: Insertion of sebaceous glands into hair shaft x 10
Organ system [videos]
An organ system is a group of organs that work together as a biological system to perform one or more functions. Each organ system does a particular job in the body, and is made up of certain tissues. — Organfunctions — These specific systems are widely studied in anatomy. They are present in …
An example of a system: the nervous system
Hair follicle [videos]
The hair follicle is a dynamic organ found in mammalian skin. It resides in the dermal layer of the skin and is made up of 20 different cell types, each with distinct functions. The hair follicle regulates hair growth via a complex interaction between hormones, neuropeptides and immune cells. This …
A photograph of hair on a human arm emerging from follicles
Hair care [videos]
Hair care is an overall term for hygiene and cosmetology involving the hair which grows from the human scalp, and to a lesser extent facial, pubic and other body hair. Hair care routines differ according to an individual's culture and the physical characteristics of one's hair. Hair may be colored …
Human hair close-up
Biomaterial [videos]
A biomaterial is any substance that has been engineered to interact with biological systems for a medical purpose - either a therapeutic or a diagnostic one. As a science, biomaterials is about fifty years old. The study of …
A hip implant is an example of an application of biomaterials
Millimetre [videos]
The millimetre or millimeter is a unit of length in the metric system, equal to one thousandth of a metre, which is the SI base unit of length. Therefore, there are one …
Ruler with millimetre and centimetre marks
Skin [videos]
Skin is the soft outer tissue covering of vertebrates with three main functions: protection, regulation, and sensation.Other animal coverings, such as the arthropod exoskeleton, have different developmental origin, structure and chemical composition. The adjective cutaneous means "of the skin" …
Skin of an elephant
Henle's layer [videos]
Henle's layer is the third and the outermost layer of the inner root sheath of the hair follicle, consisting of a single layer of cubical cells with clear flattened nuclei. It is named after German physician, pathologist and anatomist Friedrich Gustav Jakob Henle. — References — This article …
Transverse section of hair follicle.
Tom Brady [videos]
Thomas Edward Patrick Brady Jr. is an American football quarterback for the New England Patriots of the National Football League. He has won six Super Bowls, the most of any football player ever, and due to his numerous accomplishments, records, and accolades, he is …
Brady in 2017
Brady at Michigan Stadium in 2016
Brady during Super Bowl XXXIX
Brady on the sideline at Giants Stadium with teammates Randy Moss and Jabar Gaffney, after throwing for his record-breaking 50th passing touchdown of the 2007 season
Nicole Kidman [videos]
Nicole Mary Kidman is an Australian actress and producer. She began her acting career in Australia with the 1983 films Bush Christmas and BMX Bandits. Her breakthrough came in 1989 with the thriller Dead Calm and the television miniseries Bangkok Hilton. In 1990, she made her …
Kidman at the 2017 Cannes Film Festival
Kidman at the 2001 Cannes Film Festival premiere of Moulin Rouge!
Kidman in 2004
Kidman at the 2014 Cannes Film Festival premiere of Grace of Monaco
Anne, Queen of Great Britain [videos]
Anne was the Queen of England, Scotland and Ireland between 8 March 1702 and 1 May 1707. On 1 May 1707, under the Acts of Union, two of her realms, the kingdoms of England and Scotland, united as a single sovereign state known as Great Britain. She continued to …
Portrait by Michael Dahl, 1705
Anne (centre) and her sister Mary (left) with their parents, the Duke and Duchess of York, painted by Peter Lely and Benedetto Gennari II
Anne, circa 1684, painted by Willem Wissing and Jan van der Vaardt
Mary of Modena and James Francis Edward, Anne's stepmother and half-brother
History of Ireland [videos]
The first evidence of human presence in Ireland dates to about 12,500 years ago, shortly after the receding of the ice after the younger Dryas cold phase of the Quaternary ended around 9700 BC, and heralds the beginning of Prehistoric Ireland, which includes the archaeological periods known as the …
Kevin's monastery at Glendalough, County Wicklow
A page from the Book of Kells that opens the Gospel of John
A tower house near Quin, County Clare. The Normans consolidated their presence in Ireland by building hundreds of castles and towers such as this.
Irish soldiers, 1521 – by Albrecht Dürer.
Lille [videos]
Lille is a city at the northern tip of France, in French Flanders. On the Deûle River, near France's border with Belgium, it is the capital of the Hauts-de-France region, the prefecture of the Nord department, and …
Lille city centre.
The 'Vieille Bourse' on the 'Grand Place'
Entrance to the 'Vauban Citadel' (17th century)
The black dots around the windows (not the decorative cartouches) are Austrian cannonballs lodged in the façade.
Henry IV of France [videos]
Henry IV, also known by the epithet Good King Henry or Henry the Great, was King of Navarre from 1572 and King of France from 1589 to 1610. He was the first monarch of France from the House of …
Henry III of France on his deathbed designating Henry IV of Navarre as his successor (1589)
Jeton with portrait of King Henri IV, made in Nuremberg (Germany) by Hans Laufer
Entrance of Henry IV in Paris, 22 March 1594, with 1,500 cuirassiers
Henry IV and Marie de Médicis
Mercedes-Benz W196 [videos]
The Mercedes-Benz W196 was a Formula One racing car produced by Mercedes-Benz for the 1954 and 1955 F1 seasons. Successor to the W194, in the hands of Juan Manuel Fangio and Stirling Moss it won 9 of 12 races entered and captured the only two world championships in which it competed. — Firsts …
Karl Kling driving a W196 at the Nürburgring
Streamlined Type Monza bodywork
A 1954 Mercedes W196 on display at the Indianapolis Motor Speedway's Hall of Fame and Museum
Stirling Moss presenting a W196 at the 2014 Goodwood Festival of Speed
Berlin [videos]
Berlin is the capital and largest city of Germany by both area and population. Its 3,748,148 inhabitants make it the second most populous city proper of the European Union after London. The city is one of Germany's 16 federal states. It is surrounded by …
Frederick the Great (1712–1786) was one of Europe's enlightened monarchs.
Berlin became the capital of the German Empire in 1871 and expanded rapidly in the following years. (Unter den Linden in 1900)
Street, Berlin (1913) by Ernst Ludwig Kirchner
Berlin in ruins after the Second World War (Potsdamer Platz, 1945)
Order of the Garter [videos]
The Order of the Garter is an order of chivalry founded by Edward III in 1348 and regarded as the most prestigious British order of chivalry in England and the United …
Knights Companion in the procession to St George's Chapel, Windsor Castle for the Garter Service
Emperor Taishō in the robes of the Order of the Garter, as a consequence of the Anglo-Japanese Alliance
Officers of the Order of the Garter (left to right): Secretary (barely visible), Black Rod, Garter Principal King of Arms, Register, Prelate, Chancellor.
The Garter "Star" above, and "Great George" below (the knight on horseback)
Ichiro Suzuki [videos]
Ichiro Suzuki, often referred to mononymously as Ichiro, is a Japanese former professional baseball outfielder who played 28 seasons combined in top-level professional leagues. He spent the bulk of his career with two teams: nine seasons …
Ichiro with the Miami Marlins in 2016
Ichiro in July 2001
Ichiro Suzuki at the World Baseball Classic 2006
Ichiro rounding the bases on September 22, 2007
Sovereign Military Order of Malta [videos]
The Sovereign Military Order of Malta, officially the Sovereign Military Hospitaller Order of Saint John of Jerusalem, of Rhodes and of Malta (Italian: Sovrano Militare Ordine Ospedaliero di San Giovanni di Gerusalemme di Rodi e di Malta; Latin: Supremus Militaris Ordo Hospitalarius Sancti …
Bust portrait of a Knight of Malta
The Battle of Lepanto (1571), unknown artist, late 16th century
Emperor Paul wearing the Crown of the Grand Master of the Order of Malta (1799).
Palazzo Malta, Rome, Italy
Battle of Poitiers [videos]
The Battle of Poitiers was a major English victory in the Edwardian phase of the Hundred Years' War. It was fought on 19 September 1356 in Nouaillé, near the city of Poitiers in Aquitaine, western France. Edward, the Black Prince, led an army of English, Welsh, Breton and Gascon troops, many of …
The Battle of Poitiers (1356) Eugène Delacroix
Battle of Poitiers (miniature of Froissart)
Jean II, the Good, being captured.