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Hair Anatomy
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, gender, or religion. Overview Meaning 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 or root. This organ is located in the dermis and maintains stem cells, which not only re-grow the hair after it falls o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scanning Electron Microscopy
A scanning electron microscope (SEM) is a type of electron microscope that produces images of a sample by scanning the surface with a focused beam of electrons. The electrons interact with atoms in the sample, producing various signals that contain information about the surface topography and composition. The electron beam is scanned in a raster scan pattern, and the position of the beam is combined with the Intensity (physics), intensity of the detected signal to produce an image. In the most common SEM mode, secondary electrons emitted by atoms excited by the electron beam are detected using a secondary electron detector (Everhart–Thornley detector). The number of secondary electrons that can be detected, and thus the signal intensity, depends, among other things, on specimen topography. Some SEMs can achieve resolutions better than 1 Nanometre, nanometer. Specimens are observed in high vacuum in a Convention (norm), conventional SEM, or in low vacuum or wet conditions in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hairstyle
A hairstyle, hairdo, haircut, or coiffure refers to the styling of hair, usually on the human head but sometimes on the face or body. The fashioning of hair can be considered an aspect of personal grooming, fashion, and cosmetics, although practical, cultural, and popular considerations also influence some hairstyles. The oldest known depiction of hair styling is hair braiding, which dates back about 30,000 years. Women's hair was often elaborately and carefully dressed in special ways, though it was also frequently kept covered outside the home, especially for married women. Prehistory and history People's hairstyles are largely determined by the fashions of the culture they live in. Hairstyles are markers and signifiers of social class, age, marital status, racial identification, political beliefs, and attitudes about gender. Some people may cover their hair totally or partially for cultural or religious reasons. Notable examples of head covering include women in Islam w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Halifax, West Yorkshire
Halifax is a town in the Metropolitan Borough of Calderdale, in West Yorkshire, England. It is in the eastern foothills of the Pennines. In the 15th century, the town became an economic hub of the old West Riding of Yorkshire, primarily in woollen manufacture with the large Piece Hall square later built for trading wool in the town centre. The town was a thriving mill town during the Industrial Revolution with the Dean Clough Mill buildings a surviving landmark. In 2021, it had a population of 88,109. It is also the administrative centre of the wider Calderdale Metropolitan Borough. Toponymy The town's name was recorded in about 1091 as ''Halyfax'', most likely from the Old English ''halh-gefeaxe'', meaning "area of coarse grass in the of land". This explanation is generally preferred to derivations from the Old English ' (holy), in ''hālig feax'' or "holy hair", proposed by 16th-century antiquarians. The probably-incorrect interpretation gave rise to two legends. One concern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fairfax (name)
Fairfax is both a surname of English (Yorkshire and Northumberland, with a few branches later settling in Scotland) origin which means "fair hair", and a given name. Notable people with the name include: Surname: * Alan Fairfax (1906–1955), Australian cricketer * Betty Fairfax (?-2010), American educator, counselor, and philanthropist * Daphne Fairfax, a British comedian * Edward Fairfax, translator * Henry Fairfax (Royal Navy officer), British Admiral and Naval Commander K.C.B., F.R.G.S., * James Fairfax (1933–2017), Australian businessman and philanthropist * Jean E. Fairfax (1920–2019), American educator, civil rights worker, community organizer, and philanthropist * John Fairfax (other), name of several notable people :* John Fairfax (delegate) (1762–1843), manager for George Washington :* John Fairfax (minister) (1623–1700), English ejected minister :* John Fairfax, 11th Lord Fairfax of Cameron (1830–1900), British peer with American citizenship ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dutch Language
Dutch ( ) is a West Germanic languages, West Germanic language of the Indo-European language family, spoken by about 25 million people as a first language and 5 million as a second language and is the List of languages by total number of speakers, third most spoken Germanic language. In Europe, Dutch is the native language of most of the population of the Netherlands and Flanders (which includes 60% of the population of Belgium). "1% of the EU population claims to speak Dutch well enough in order to have a conversation." (page 153). Dutch was one of the official languages of South Africa until 1925, when it was replaced by Afrikaans, a separate but partially Mutual intelligibility, mutually intelligible daughter language of Dutch. Afrikaans, depending on the definition used, may be considered a sister language, spoken, to some degree, by at least 16 million people, mainly in South Africa and Namibia, and evolving from Cape Dutch dialects. In South America, Dutch is the native l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medulla (hair)
The medulla is the innermost layer of the hair shaft. This nearly invisible layer is the most soft and fragile, and serves as the pith or marrow of the hair. Some mammals don't have a medulla in their hair. The presence or absence of this layer and the characteristics of the medulla can aid taxonomists in identifying what taxa a hair comes from. Characteristics include whether the medulla contains air pockets as well as the histology of the medulla. Scientists are still uncertain about the exact role of the medulla, but they speculate that it is primarily an extension that is more prominent in depigmented (grey or white) hair .James, William; Berger, Timothy; Elston, Dirk (2005) ''Andrews' Diseases of the Skin: Clinical Dermatology'' (10th ed.). Saunders. Page 8. . See also List of distinct cell types in the adult human body The list of human cell types provides an enumeration and description of the various specialized cells found within the human body, highlighting thei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cortex (hair)
The cortex of the hair shaft is located between the hair cuticle and medulla and is the thickest hair layer. It contains most of the hair's pigment, giving the hair its color. The major pigment in the cortex is melanin, which is also found in skin. The distribution of this pigment varies from animal to animal and person to person. In humans, the melanin is primarily denser nearer the cuticle whereas in animals, melanin is primarily denser nearer the medulla.James, William; Berger, Timothy; Elston, Dirk (2005) ''Andrews' Diseases of the Skin: Clinical Dermatology'' (10th ed.). Saunders. Page 8. . See also * List of distinct cell types in the adult human body The list of human cell types provides an enumeration and description of the various specialized cells found within the human body, highlighting their distinct functions, characteristics, and contributions to overall physiological processes. Cell ... References Hair anatomy {{Dermatology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cuticle (hair)
Comparison of sheep (top) and human (bottom) hairs with different cuticle textures The hair cuticle is the outermost part of the hair shaft.James, William; Berger, Timothy; Elston, Dirk (2005) ''Andrews' Diseases of the Skin: Clinical Dermatology'' (10th ed.). Saunders. Page 8. . It is formed from dead cells, overlapping in layers, which form scales that strengthen and protect the hair shaft. These layers are formed of keratin proteins. The hair cuticle is also known to contain anteiso-18-methyleicosanoic acid which contribute to the hydrophobic properties of hair. Diagram of the hair shaft, indicating medulla (innermost), cortex, and cuticle (exterior) While the cuticle is the outermost layer, it is not responsible for the color of the hair. Melanin is the pigment A pigment is a powder used to add or alter color or change visual appearance. Pigments are completely or nearly solubility, insoluble and reactivity (chemistry), chemically unreactive in water or another m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Keratin
Keratin () is one of a family of structural fibrous proteins also known as ''scleroproteins''. It is the key structural material making up Scale (anatomy), scales, hair, Nail (anatomy), nails, feathers, horn (anatomy), horns, claws, Hoof, hooves, and the outer layer of skin in vertebrates. Keratin also protects epithelial cells from damage or stress. Keratin is extremely insoluble in water and organic solvents. Keratin monomers assemble into bundles to form intermediate filaments, which are tough and form strong mineralization (biology), unmineralized epidermal appendages found in reptiles, birds, amphibians, and mammals. Excessive keratinization participate in fortification of certain tissues such as in horns of cattle and rhinos, and armadillos' osteoderm. The only other biology, biological matter known to approximate the toughness of keratinized tissue is chitin. Keratin comes in two types: the primitive, softer forms found in all vertebrates and the harder, derived forms fou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wound
A wound is any disruption of or damage to living tissue, such as skin, mucous membranes, or organs. Wounds can either be the sudden result of direct trauma (mechanical, thermal, chemical), or can develop slowly over time due to underlying disease processes such as diabetes mellitus, venous/arterial insufficiency, or immunologic disease. Wounds can vary greatly in their appearance depending on wound location, injury mechanism, depth of injury, timing of onset ( acute vs chronic), and wound sterility, among other factors. Treatment strategies for wounds will vary based on the classification of the wound, therefore it is essential that wounds be thoroughly evaluated by a healthcare professional for proper management. In normal physiology, all wounds will undergo a series of steps collectively known as the wound healing process, which include hemostasis, inflammation, proliferation, and tissue remodeling. Age, tissue oxygenation, stress, underlying medical conditions, and certain m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stem Cell
In multicellular organisms, stem cells are undifferentiated or partially differentiated cells that can change into various types of cells and proliferate indefinitely to produce more of the same stem cell. They are the earliest type of cell in a cell lineage. They are found in both embryonic and adult organisms, but they have slightly different properties in each. They are usually distinguished from progenitor cells, which cannot divide indefinitely, and precursor or blast cells, which are usually committed to differentiating into one cell type. In mammals, roughly 50 to 150 cells make up the inner cell mass during the blastocyst stage of embryonic development, around days 5–14. These have stem-cell capability. '' In vivo'', they eventually differentiate into all of the body's cell types (making them pluripotent). This process starts with the differentiation into the three germ layers – the ectoderm, mesoderm and endoderm – at the gastrulation stage. However, whe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
506 Hair
5 (five) is a number, numeral and digit. It is the natural number, and cardinal number, following 4 and preceding 6, and is a prime number. Humans, and many other animals, have 5 digits on their limbs. Mathematics 5 is a Fermat prime, a Mersenne prime exponent, as well as a Fibonacci number. 5 is the first congruent number, as well as the length of the hypotenuse of the smallest integer-sided right triangle, making part of the smallest Pythagorean triple ( 3, 4, 5). 5 is the first safe prime and the first good prime. 11 forms the first pair of sexy primes with 5. 5 is the second Fermat prime, of a total of five known Fermat primes. 5 is also the first of three known Wilson primes (5, 13, 563). Geometry A shape with five sides is called a pentagon. The pentagon is the first regular polygon that does not tile the plane with copies of itself. It is the largest face any of the five regular three-dimensional regular Platonic solid can have. A conic is determ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
