Human scalp hair normally grows at a rate of 0.4 mm /day (incidentally human scalp hair grows at a rate four times that of human nails. Human nails grow at a rate of 0.1 mm/day). As far as the growth after death, it is a myth; the appearance of growth is actually caused by the retraction of skin as the surrounding tissue dehydrates, making nails and hair more prominent
Hair texture is described as fine, medium, coarse or wiry, depending on the hair diameter. Within the four texture ranges hair can also be thin, medium or thick density and it can be straight, curly, 'kinky' (tightly coiled), or wavy. Hair conditioner also affects hair texture. Hair can be healthy, normal, oily, dry, damaged or a combination. Hair texture can also be affected by hair styling equipment such as straighteners, crimpers, or curlers. Also, a hairdresser can change hair texture with chemicals.
Hair is genetically programmed to be straight, wavy, curly, or 'kinky,' and it can change over time.
For many years, it was believed that the shape of a person’s hair was determined by the individual hair shafts, and that curly and 'kinky' hair get their shape because the cross-section of the hair shaft was flatter and had more intertwined layers than straight hair, which was round. But scientists have determined that whether your hair is curly, 'kinky', or straight is determined by the shape of the follicle itself and the direction in which each strand grows out of its follicle. Curly and/or 'kinky' hair is shaped like an elongated oval and grows at a sharp angle to the scalp. This growth pattern, in turn, determines the cross-section of the shafts. Curly and/or 'kinky' hair has a different biological structure from straight hair. It tends to be much drier than straight hair because the oils secreted into the hair shaft by the sebaceous glands can more easily travel down the shaft of straight hair. People with very curly hair may find that this hair type can be dry and often frizzy.
Hair texture is described as fine, medium, coarse or wiry, depending on the hair diameter. Within the four texture ranges hair can also be thin, medium or thick density and it can be straight, curly, 'kinky' (tightly coiled), or wavy. Hair conditioner also affects hair texture. Hair can be healthy, normal, oily, dry, damaged or a combination. Hair texture can also be affected by hair styling equipment such as straighteners, crimpers, or curlers. Also, a hairdresser can change hair texture with chemicals.
Hair is genetically programmed to be straight, wavy, curly, or 'kinky,' and it can change over time.
For many years, it was believed that the shape of a person’s hair was determined by the individual hair shafts, and that curly and 'kinky' hair get their shape because the cross-section of the hair shaft was flatter and had more intertwined layers than straight hair, which was round. But scientists have determined that whether your hair is curly, 'kinky', or straight is determined by the shape of the follicle itself and the direction in which each strand grows out of its follicle. Curly and/or 'kinky' hair is shaped like an elongated oval and grows at a sharp angle to the scalp. This growth pattern, in turn, determines the cross-section of the shafts. Curly and/or 'kinky' hair has a different biological structure from straight hair. It tends to be much drier than straight hair because the oils secreted into the hair shaft by the sebaceous glands can more easily travel down the shaft of straight hair. People with very curly hair may find that this hair type can be dry and often frizzy.
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