January 20, 2015 @ HealthHype
The human lips (labia oris) is the junction between the outer facial skin and inner buccal mucosa that lines the mouth cavity. The outer layers are largely similar to skin except that the lips has fewer layers. The color of skin is determined by the amount of natural pigment known as melanin. Melanocytes are specialized pigment cells that produce melanin in smaller quantities than elsewhere on the skin. The lips also have melanin but to a much lesser degree than the rest of the skin.
This lower quantity of melanin is genetically determined but is further regulated by exposure to ultraviolet light mainly from sunlight and less frequently from tanning beds. Combined with its fewer layers of skin than the rest of the face, the color of the lips is also largely dependent on the underlying tissue color and blood flow. This is the reason that the lips are a pink to red color.
Most cases of discolored lips are associated with brownish to brownish-gray hue. The lips itself almost never reaches a full black color. However, other colors such as bluish or yellowish discoloration may also occur. It can be associated with environmental causes, mechanical, chemical or electromagnetic damage, skin disorders, systemic diseases and lifestyle factors.
Anemia, Cyanosis, Lifestyle Factors, Lentigo,Peutz-Jeghers Syndrome, Melasma etc
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