Hair, a defining characteristic of mammals, is a protein filament that grows from follicles found in the dermis layer of skin. It is a complex biomaterial primarily composed of keratin, the same protein that forms fingernails and toenails. It also contains a mixture of lipids that gives it its sheen and flexibility.
The follicle that produces your hair is called a papilla, and it sits under the surface of your scalp in the dermis layer of skin. Each follicle has a sebaceous gland that produces lipid-rich sebum, which naturally protects the hair and moisturizes the skin around it. At the base of each follicle is a hair bulb, where the actual hair growth process takes place. As blood vessels deliver nutrients to the follicle, cells in the hair bulb begin to multiply and grow longer, eventually producing the strands of hair.
When a new strand forms, it moves up through the follicle, and old cells are pushed outward and shed. This process repeats itself, and eventually the strand of hair becomes long enough to be visible. The size of the follicle determines its thickness, and the shape of the follicle determines whether your hair is straight, curly or wavy. The follicle is surrounded by a sheath of fat and muscle that adds to its strength, and the strand of hair itself is composed of proteins and lipids that give it elasticity and strength.
A hair’s tensile strength is comparable to that of steel, which explains why it can be stretched so far before it breaks. It is also flexible, allowing it to move with the contours of your head and body without breaking. Hair is made of a strong fibrous protein known as keratin, and it is built from the same cells that make up the skin on your face and hands.
Hair has many functions, including providing insulation and protecting the scalp from sun damage. It is also a symbol of identity, and it can indicate your gender, ethnicity, worldview or socioeconomic status. Unfortunately, it is also a source of stereotypes, and people are often judged based on their appearance.
Whether you want to write about your relationship with your grandma or your struggle with your natural hair texture, the most important thing to remember is to keep the focus on yourself. Using your hair as a way to discuss someone else can come off as disingenuous and may not help you stand out from the other applicants on a college application.