Human hair has multiple functions. It protects the head from sun damage, traps air beneath the outermost layer of the hair shaft, and signals to other animals. The hair also extends the sense of touch beyond the skin. It gives warning signals, and is an important part of animal identity. Interestingly, ancient myths speak of hair’s power to attract and seduce. For example, Rapunzel’s hair was interpreted as a tale of hair’s ability to allure and connect. It is also considered a source of mystical strength in Samson. The countless uses for hair extend far beyond cosmetics.
Different types of hair have different textures and appearances. The shape of the hair follicle determines its texture. Oval-shaped follicles produce curly hair, while round-shaped cells create straighter hair. Genetics heavily affect hair shapes, though they can change with age. Depending on your family history, you may have curly hair for your entire life. Listed below are some hair types and how they change over the years.
Hair follicles are located deep in the dermis and often project into the subcutaneous layer below. The follicle contains a flat, cuticle-like covering of cells, surrounded by a small papilla. In addition, it contains capillaries and nerves. The hair bulb is made of epithelial cells and keratinized cells and forms the outer covering of the hair. The cuticle protects the hair from environmental factors.
In addition to being an important part of a person’s appearance, hair can also be a marker of a person’s group membership. For instance, the following of Oliver Cromwell had their hair cut very short and trimmed close to the head, earning them the name Roundheads. Hair analysis can reveal the sociocultural interaction that took place in the 19th century. In the 1920s, bobbed hair was fashionable among flappers and female art students.
Human hair consists of protein filaments that project out of the skin’s surface in almost every area. Its density is high, ranging from ten to twenty-four thousand per square cents. Most body hair is vellus hairs, which are colorless and thin, while terminal hairs are thick, pigmented, and coarse. Hair follicles contain about 5 million hair follicles, with roughly 100,000 in the scalp.
The follicle is a diagonal tube containing a hair root. It has two main layers: the epithelial root sheath, which is a stratified squamous epithelium that lies adjacent to the hair root, and the connective tissue root sheath, which is made of collagenous connective tissue that surrounds the entire follicle. Although the medullary layer is present in some hairs, it is not present in all.
The hair follicles on the head go through periods of activity and dormancy. A hair follicle on average loses about fifty to one hundred hairs per day. Hair grows and falls out every two to six years, and new ones develop to replace them. This process is referred to as the hair cycle. The growth and falling out of hair is a natural part of the human life cycle. But it’s important to understand the cycles of hair growth and fall.