Head hair

Head hair

Young Girl Fixing her Hair, by Sophie Gengembre AndersonHead hair is a type of hair that is grown on the head (sometimes referring directly to the scalp). The most noticeable part of human hair is the hair on the head, which can grow longer than on most mammals and is more dense than most hair found elsewhere on the body. The average human head has about 100,000 hair follicles. [1] Its absence is termed alopecia, commonly known as baldness. Anthropologists speculate that the functional significance of long head hair may be adornment, a by-product of secondary natural selection once other somatic hair had been lost. Another possibility is that long head hair is a result of Fisherian runaway sexual selection, where long lustrous hair is a visible marker for a healthy individual (with good nutrition, waist length hair—approximately 1 meter or 39 inches long—would take around 84 months, or about 7 years, to grow). Each follicle can grow about 20 individual hairs in a person's lifetime. [2] Average hair loss is about 100 strands a day. The average human scalp measures approximately 770 cm² (120 square inches). These values are also reported by Desmond Morris[4] although it is not clear if these apply to both men and women. Average number of head hairs (Caucasian)