Search results
Results from the WOW.Com Content Network
Phototoxicity, also called photoirritation, is a chemically induced skin irritation, requiring light, that does not involve the immune system. [1] It is a type of photosensitivity. [1] [2] The skin response resembles an exaggerated sunburn.
Melanocytes are melanin-producing neural crest-derived [3] cells located in the bottom layer (the stratum basale) of the skin's epidermis, the middle layer of the eye (the uvea), [4] the inner ear, [5] vaginal epithelium, [6] meninges, [7] bones, [8] and heart found in many mammals and birds. [9] Melanin is a dark pigment primarily responsible ...
Poikiloderma is a skin condition that consists of areas of hypopigmentation, hyperpigmentation, telangiectasias and atrophy. Poikiloderma of Civatte is most frequently seen on the chest or the neck, characterized by red colored pigment on the skin that is commonly associated with sun damage.
This is an accepted version of this page This is the latest accepted revision, reviewed on 28 January 2025. "Skin pigmentation" redirects here. For animal skin pigmentation, see Biological pigment. Extended Coloured family from South Africa showing some spectrum of human skin coloration Human skin color ranges from the darkest brown to the lightest hues. Differences in skin color among ...
Hyperpigmentation can be diffuse or focal, affecting such areas as the face and the back of the hands. Melanin is produced by melanocytes at the lower layer of the epidermis . Melanin is a class of pigment responsible for producing color in the body in places such as the eyes, skin, and hair.
Acanthosis nigricans is a medical sign characterised by brown-to-black, poorly defined, velvety hyperpigmentation of the skin. [1] It is usually found in body folds, [2] such as the posterior and lateral folds of the neck, the armpits, groin, navel, forehead and other areas.
They have a dominant gene that causes hyperpigmentation (Fibromelanosis), making the chicken entirely black; including feathers, beak, and internal organs. Melanism in feral rock doves are actually quite common,to some extent, especially if the area is abundant with the species. The amount of pigmentation is varied, from a slight darker ...
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 .