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Pachyderma
Pachyderma, or pachydermia, is the thickening of skin like that of a pachyderm (a tough-skinned animal such as an elephant, rhinoceros, tapir or hippopotamus). It occurs in the condition pachydermoperiostosis, an autosomal genetic disorder. It can also occur in acromegaly, elephantiasis Elephantiasis is the enlargement and hardening of limbs or body parts due to tissue swelling. It is characterised by edema, hypertrophy, and fibrosis of skin and subcutaneous tissues, due to obstruction of lymphatic vessels. It may affect the geni ..., and podoconiosis. The adjective pachydermatous is used to describe skin showing symptoms of this condition. References External links Genodermatoses {{dermatology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pachydermata
Pachydermata (meaning 'thick skin', from the Greek grc, παχύς, pachys, thick, label=none, and grc, δέρμα, derma, skin, label=none) is an obsolete order of mammals described by Gottlieb Storr, Georges Cuvier, and others, at one time recognized by many systematists. Because it is polyphyletic, the order is no longer in use, but it is important in the history of systematics. Outside strict biological classification, the term "" remains commonly used to describe elephants, rhinoceroses, tapirs, and hippopotamuses. Cuvier's Pachydermata included the three families of mammals he called Proboscidiana, Pachydermata Ordinaria, and Solipedes, all herbivorous. They are now divided into the Proboscidea (represented among living species only by three species of elephants), the Perissodactyla (odd-toed ungulates, including horses, tapirs and rhinoceroses), the Suina (pigs and peccaries), the Hippopotamidae, and the Hyracoidea (hyraxes). Thanks to genetic studies, elephants, rhin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Skin
Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate animal, with three main functions: protection, regulation, and sensation. Other cuticle, animal coverings, such as the arthropod exoskeleton, have different cellular differentiation, developmental origin, structure and chemical composition. The adjective cutaneous means "of the skin" (from Latin ''cutis'' 'skin'). In mammals, the skin is an organ (anatomy), organ of the integumentary system made up of multiple layers of ectodermal tissue (biology), tissue and guards the underlying muscles, bones, ligaments, and internal organs. Skin of a different nature exists in amphibians, reptiles, and birds. Skin (including cutaneous and subcutaneous tissues) plays crucial roles in formation, structure, and function of extraskeletal apparatus such as horns of bovids (e.g., cattle) and rhinos, cervids' antlers, giraffids' ossicones, armadillos' osteoderm, and os penis/os clitoris. All mammals have som ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elephant
Elephants are the largest existing land animals. Three living species are currently recognised: the African bush elephant, the African forest elephant, and the Asian elephant. They are the only surviving members of the family Elephantidae and the order Proboscidea. The order was formerly much more diverse during the Pleistocene, but most species became extinct during the Late Pleistocene epoch. Distinctive features of elephants include a long proboscis called a trunk, tusks, large ear flaps, pillar-like legs, and tough but sensitive skin. The trunk is used for breathing, bringing food and water to the mouth, and grasping objects. Tusks, which are derived from the incisor teeth, serve both as weapons and as tools for moving objects and digging. The large ear flaps assist in maintaining a constant body temperature as well as in communication. African elephants have larger ears and concave backs, whereas Asian elephants have smaller ears, and convex or level backs. Elephants ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhinoceros
A rhinoceros (; ; ), commonly abbreviated to rhino, is a member of any of the five extant species (or numerous extinct species) of odd-toed ungulates in the family Rhinocerotidae. (It can also refer to a member of any of the extinct species of the superfamily Rhinocerotoidea.) Two of the extant species are native to Africa, and three to South and Southeast Asia. Rhinoceroses are some of the largest remaining megafauna: all weigh at least one tonne in adulthood. They have a herbivorous diet, small brains (400–600 g) for mammals of their size, one or two horns, and a thick (1.5–5 cm), protective skin formed from layers of collagen positioned in a lattice structure. They generally eat leafy material, although their ability to ferment food in their hindgut allows them to subsist on more fibrous plant matter when necessary. Unlike other perissodactyls, the two African species of rhinoceros lack teeth at the front of their mouths; they rely instead on their lips to pl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tapir
Tapirs ( ) are large, herbivorous mammals belonging to the family Tapiridae. They are similar in shape to a pig, with a short, prehensile nose trunk. Tapirs inhabit jungle and forest regions of South and Central America, with one species inhabiting Southeast Asia. They are one of three extant branches of Perissodactyla (odd-toed ungulates), alongside equines and rhinoceros. Only a single genus, ''Tapirus'' is currently extant. Tapirs migrated into South America during the Pleistocene epoch from North America after the formation of the Isthmus of Panama as part of the Great American Interchange. Tapirs were once widespread in North America until the arrival of humans at the end of the Late Pleistocene, around 12,000 years ago. Species There are four widely recognized extant species of tapir, all in the genus ''Tapirus'' of the family Tapiridae. They are the South American tapir, the Malayan tapir, Baird's tapir, and the mountain tapir. In 2013, a group of researchers said they ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hippopotamus
The hippopotamus ( ; : hippopotamuses or hippopotami; ''Hippopotamus amphibius''), also called the hippo, common hippopotamus, or river hippopotamus, is a large semiaquatic mammal native to sub-Saharan Africa. It is one of only two extant species in the family Hippopotamidae, the other being the pygmy hippopotamus (''Choeropsis liberiensis'' or ''Hexaprotodon liberiensis''). Its name comes from the ancient Greek for "river horse" (). Aside from elephants and rhinos, the hippopotamus is the largest land mammal. It is also the largest extant land artiodactyl. Despite their physical resemblance to pigs and other terrestrial even-toed ungulates, the closest living relatives of the hippopotamids are cetaceans (whales, dolphins, porpoises, etc.), from which they diverged about 55 million years ago. Hippos are recognisable for their barrel-shaped torsos, wide-opening mouths with large canine tusks, nearly hairless bodies, pillar-like legs, and large size: adults average ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pachydermoperiostosis
Pachydermoperiostosis (PDP) is a rare genetic disorder that affects both bones and skin. Other names are primary hypertrophic osteoarthropathy or Touraine-Solente-Golé syndrome. It is mainly characterized by pachyderma (thickening of the skin), periostosis (excessive bone formation) and finger clubbing (swelling of tissue with loss of normal angle between nail and nail bed). This disease affects more men than women. After onset, the disease stabilizes after about 5–20 years. Life of PDP patients can be severely impaired. Currently, symptomatic treatments are NSAIDs and steroids or surgical procedures. In 1868, PDP was first described by Friedreich as 'excessive growth of bone of the entire skeleton'. Touraine, Solente and Golé described PDP as the primary form of bone disease hypertrophic osteoarthropathy in 1935 and distinguished its three known forms. Symptoms PDP has a number of visible signs. Most important clinical features are: pachydermia (thickening and wrinkling ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autosomal
An autosome is any chromosome that is not a sex chromosome. The members of an autosome pair in a diploid cell have the same morphology, unlike those in allosome, allosomal (sex chromosome) pairs, which may have different structures. The DNA in autosomes is collectively known as atDNA or auDNA. For example, humans have a diploid human genome, genome that usually contains 22 pairs of autosomes and one allosome pair (46 chromosomes total). The autosome pairs are labeled with numbers (1–22 in humans) roughly in order of their sizes in base pairs, while allosomes are labelled with their letters. By contrast, the allosome pair consists of two X chromosomes in females or one X and one Y chromosome in males. Unusual combinations of XYY syndrome, XYY, Klinefelter syndrome, XXY, Triple X syndrome, XXX, XXXX syndrome, XXXX, XXXXX syndrome, XXXXX or XXYY syndrome, XXYY, among Aneuploidy, other Salome combinations, are known to occur and usually cause developmental abnormalities. Autosomes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetic Disorder
A genetic disorder is a health problem caused by one or more abnormalities in the genome. It can be caused by a mutation in a single gene (monogenic) or multiple genes (polygenic) or by a chromosomal abnormality. Although polygenic disorders are the most common, the term is mostly used when discussing disorders with a single genetic cause, either in a gene or chromosome. The mutation responsible can occur spontaneously before embryonic development (a ''de novo'' mutation), or it can be Heredity, inherited from two parents who are carriers of a faulty gene (autosomal recessive inheritance) or from a parent with the disorder (autosomal dominant inheritance). When the genetic disorder is inherited from one or both parents, it is also classified as a hereditary disease. Some disorders are caused by a mutation on the X chromosome and have X-linked inheritance. Very few disorders are inherited on the Y linkage, Y chromosome or Mitochondrial disease#Causes, mitochondrial DNA (due to t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acromegaly
Acromegaly is a disorder that results from excess growth hormone (GH) after the growth plates have closed. The initial symptom is typically enlargement of the hands and feet. There may also be an enlargement of the forehead, jaw, and nose. Other symptoms may include joint pain, thicker skin, deepening of the voice, headaches, and problems with vision. Complications of the disease may include type 2 diabetes, sleep apnea, and high blood pressure. Acromegaly is usually caused by the pituitary gland producing excess growth hormone. In more than 95% of cases the excess production is due to a benign tumor, known as a pituitary adenoma. The condition is not inherited from a person's parents. Acromegaly is rarely due to a tumor in another part of the body. Diagnosis is by measuring growth hormone after a person has consumed a glucose solution, or by measuring insulin-like growth factor I in the blood. After diagnosis, medical imaging of the pituitary is carried out to determine if an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elephantiasis
Elephantiasis is the enlargement and hardening of limbs or body parts due to tissue swelling. It is characterised by edema, hypertrophy, and fibrosis of skin and subcutaneous tissues, due to obstruction of lymphatic vessels. It may affect the genitalia. The term elephantiasis is often used in reference to (symptoms caused by) parasitic worm infections, but may refer to a variety of diseases where parts of a person's body swell to massive proportions. __TOC__ Cause Some conditions that present with elephantiasis include: * Elephantiasis nostras, due to longstanding chronic lymphangitis * Elephantiasis tropica (known as lymphatic filariasis), caused by a number of parasitic worms, particularly ''Wuchereria bancrofti''. More than 120 million people, mostly in Africa and Southeast Asia, are affected. * Nonfilarial elephantiasis (or podoconiosis), an immune disease affecting the lymph vessels * Leishmaniasis * Elephantiasis, Grade 3 lymphedema which may occur in people with breast cance ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Podoconiosis
Podoconiosis, also known as nonfilarial elephantiasis, is a disease of the lymphatic vessels of the lower extremities that is caused by chronic exposure to irritant soils. It is the second most common cause of tropical lymphedema after lymphatic filariasis, and it is characterized by prominent swelling of the lower extremities, which leads to disfigurement and disability. Methods of prevention include wearing shoes and using floor coverings. Mainstays of treatment include daily foot hygiene, compression bandaging, and when warranted, surgery of overlying nodules. Signs and symptoms Podoconiosis causes bilateral yet asymmetrical leg swelling with overlying firm nodules. Early on, symptoms may include itching, tingling, widening of the forefoot, and swelling which then progress to soft edema, skin fibrosis, papillomatosis, and nodule formation resembling moss, giving rise to the disease's alternate name of "mossy foot" in some regions of the world. As with other forms of tropi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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