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Hair Casts
Hair casts (also known as "Pseudonits") represent remnants of the inner root sheath, and often occur in great numbers and may mimic nits in the scalp The scalp is the anatomical area bordered by the human face at the front, and by the neck at the sides and back. Structure The scalp is usually described as having five layers, which can conveniently be remembered as a mnemonic: * S: The ski ....James, William; Berger, Timothy; Elston, Dirk (2005). ''Andrews' Diseases of the Skin: Clinical Dermatology''. (10th ed.). Saunders. . See also * List of cutaneous conditions References {{skin-appendage-stub Conditions of the skin appendages Hair diseases Human hair ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hair Follicle
The hair follicle is an 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 complex interaction induces the hair follicle to produce different types of hair as seen on different parts of the body. For example, terminal hairs grow on the scalp and lanugo hairs are seen covering the bodies of fetuses in the uterus and in some newborn babies. The process of hair growth occurs in distinct sequential stages. The first stage is called ''anagen'' and is the active growth phase, ''telogen'' is the resting stage, ''catagen'' is the regression of the hair follicle phase, ''exogen'' is the active shedding of hair phase and lastly ''kenogen'' is the phase between the empty hair follicle and the growth of new hair. The function of hair in humans has long been a subject ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Head-louse Infestation
Head lice infestation, also known as pediculosis capitis, is the infection of the head hair and scalp by the head louse (''Pediculus humanus capitis''). Itching from lice bites is common. During a person's first infection, the itch may not develop for up to six weeks. If a person is infected again, symptoms may begin much more quickly. The itch may cause problems with sleeping. Generally, however, it is not a serious condition. While head lice appear to spread some other diseases in Africa, they do not appear to do so in Europe or North America. Head lice are spread by direct contact with the hair of someone who is infected. The cause of head lice infestations in children is not related to cleanliness. Other animals, such as cats and dogs, do not play a role in transmission. Head lice feed only on human blood and are only able to survive on human head hair. When adults, they are about 2 to 3 mm long. When not attached to a human, they are unable to live beyond three da ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scalp
The scalp is the anatomical area bordered by the human face at the front, and by the neck at the sides and back. Structure The scalp is usually described as having five layers, which can conveniently be remembered as a mnemonic: * S: The skin on the head from which head hair grows. It contains numerous sebaceous glands and hair follicles. * C: Connective tissue. A dense subcutaneous layer of fat and fibrous tissue that lies beneath the skin, containing the nerves and vessels of the scalp. * A: The aponeurosis called epicranial aponeurosis (or galea aponeurotica) is the next layer. It is a tough layer of dense fibrous tissue which runs from the frontalis muscle anteriorly to the occipitalis posteriorly. * L: The loose areolar connective tissue layer provides an easy plane of separation between the upper three layers and the pericranium. In scalping the scalp is torn off through this layer. It also provides a plane of access in craniofacial surgery and neurosurgery. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Cutaneous Conditions
Many skin conditions affect the human integumentary system—the organ system covering the entire surface of the body and composed of skin, hair, nails, and related muscle and glands. The major function of this system is as a barrier against the external environment. The skin weighs an average of four kilograms, covers an area of two square metres, and is made of three distinct layers: the epidermis, dermis, and subcutaneous tissue. The two main types of human skin are: glabrous skin, the hairless skin on the palms and soles (also referred to as the "palmoplantar" surfaces), and hair-bearing skin.Burns, Tony; ''et al''. (2006) ''Rook's Textbook of Dermatology CD-ROM''. Wiley-Blackwell. . Within the latter type, the hairs occur in structures called pilosebaceous units, each with hair follicle, sebaceous gland, and associated arrector pili muscle. In the embryo, the epidermis, hair, and glands form from the ectoderm, which is chemically influenced by the underlying m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conditions Of The Skin Appendages
Condition or conditions may refer to: In philosophy and logic * Material conditional, a logical connective used to form "if...then..." statements * Necessary and sufficient condition, a statement which is true if and only if another given statement is true In science and technology In computer science * Exception handling#Condition systems, a generalization of exceptions in exception handling * Condition (SQL), a filtering mechanism in relational database queries * Condition variable, a synchronization primitive in concurrent programming In medicine * Medical condition, as a synonym for disease * Medical state or condition, a patient's clinical status in a hospital In numerical analysis * Condition number, a measure of a matrix in digital computation In arts and entertainment * ''Condition'' (film), a 2011 film * ''Conditions'' (album), 2009 debut album by Australian rock band The Temper Trap * ''Conditions'' (magazine), an annual lesbian feminist literary magazine * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hair Diseases
Hair diseases are disorders primarily associated with the follicles of the hair. A few examples are: * Bubble hair deformity * Hair casts (shedding of remnants of the inner root sheath) * Hair loss (alopecia) * Hirsutism (excessive hair on body parts with usually minimal hair) * Hypertrichosis (excessive hair growth) * Ingrown hair * Monilethrix (beaded hair) * Premature greying of hair * Pattern hair loss * Trichorrhexis invaginata (hair shaft abnormality) * Trichotillomania (hair-pulling disorder) Many hair diseases can be associated with distinct underlying disorders. Piedra are fungal diseases. Hair disease may refer to excessive shedding or baldness (or both). Balding can be localised or diffuse, scarring or non-scarring. Increased hair can be due to hormonal factors (hirsutism) or non-hormonal (hypertrichosis). Scalp disorders may or may not be associated with hair loss. See also * List of cutaneous conditions Many skin conditions affect the human integumentary sy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
