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Determining the evolutionary function of androgenic hair must take into account both human evolution and the thermal properties of hair itself. The thermodynamic properties of hair are based on the properties of the keratin strands and amino acids that combine into a 'coiled' structure. This structure lends to many of the properties of hair ...
Humans may also lose their hair as a result of hormonal imbalance due to drugs or pregnancy. [3] In order to comprehend why humans have significantly less body hair than other primates, one must understand that mammalian body hair is not merely an aesthetic characteristic; it protects the skin from wounds, bites, heat, cold, and UV radiation. [4]
Adult human bodies photographed whose naturally-occurring pubic, body, facial, but not head hair have been deliberately removed to show anatomy. Retouched with anterior and posterior views. There are functionally infinite variations in human phenotypes, though society reduces the variability to distinct categories.
Acquired characteristics can be minor and temporary like bruises, blisters, or shaving body hair. Permanent but inconspicuous or invisible ones are corrective eye surgery and organ transplant or removal. Semi-permanent but inconspicuous or invisible traits are vaccination and laser hair removal.
A girl with reddish brown hair. All natural hair colors are the result of two types of hair pigments. Both of these pigments are melanin types, produced inside the hair follicle and packed into granules found in the fibers. Eumelanin is the dominant pigment in brown hair and black hair, while pheomelanin is dominant in red hair.
Those connotations were mostly applied to women's and not men's body hair. [2] By the early 20th century, the upper- and middle-class white America increasingly saw smooth skin as a marker of femininity, and female body hair as repulsive, with hair removal giving "a way to separate oneself from cruder people, lower class and immigrant". [2]
Sebaceous glands are part of the body's integumentary system and serve to protect the body against microorganisms. Sebaceous glands secrete acids that form the acid mantle . This is a thin, slightly acidic film on the surface of the skin that acts as a barrier to microbes that might penetrate the skin. [ 20 ]
A hairdresser colors a client's hair. Hair color can be changed by a chemical process. Hair coloring is classed as "permanent" or "semi-permanent". Permanent hair color means that the hair's structure has been chemically altered until it is eventually cut away. This does not mean that the synthetic color will remain permanently.