Search results
Results from the WOW.Com Content Network
Because of the differences between mucous membranes and the skin (e.g., keratinizing mucosa does not have a stratum lucidum and non keratinizing mucosa does not have this layer or normally a stratum corneum or a stratum granulosum), sometimes specialized texts give slightly different definitions of hyperkeratosis in the context of mucosae.
Keratosis (from kerat-+ -osis) [1] is a growth of keratin on the skin or on mucous membranes stemming from keratinocytes, the prominent cell type in the epidermis. More specifically, it can refer to: actinic keratosis (also known as solar keratosis), a premalignant condition; chronic scar keratosis; hydrocarbon keratosis
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. [1] 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. [3]
In humans, they constitute 90% of epidermal skin cells. [1] Basal cells in the basal layer ( stratum basale ) of the skin are sometimes referred to as basal keratinocytes . [ 2 ] Keratinocytes form a barrier against environmental damage by heat , UV radiation , water loss , pathogenic bacteria , fungi , parasites , and viruses .
An example is the skin on the forearm, which is on average 1.3 mm in males and 1.26 mm in females. [4] One average square inch (6.5 cm 2) of skin holds 650 sweat glands, 20 blood vessels, 60,000 melanocytes, and more than 1,000 nerve endings. [5] [better source needed] The average human skin cell is about 30 μm in
Keratosis pilaris (KP; also follicular keratosis, lichen pilaris, or colloquially chicken skin. [ 1 ] ) is a common, autosomal - dominant , genetic condition of the skin's hair follicles characterized by the appearance of possibly itchy , small, gooseflesh -like bumps, with varying degrees of reddening or inflammation. [ 2 ]
Microscopy of keratin filaments inside cells. Keratin (/ ˈ k ɛr ə t ɪ n / [1] [2]) is one of a family of structural fibrous proteins also known as scleroproteins.It is the key structural material making up scales, hair, nails, feathers, horns, claws, hooves, and the outer layer of skin in vertebrates.
[4] [5] The condition is the most severe form of ichthyosis (except for syndromes that include ichthyosis, for example, Neu–Laxova syndrome), a group of genetic disorders characterised by scaly skin. [8] Harlequin-type ichthyosis is caused by mutations in the ABCA12 gene. [4]