Keratin is the protein that makes human hair. Each individual hair grows from a hair follicle which anchors to the skin. Hair is one of the main features which define us as mammals. Did you know that the hair follicle is a mammalian-specific skin organ?
Hair varies person to person. It grows in different shapes, colors, and places on different individuals. The average growth rate is one-half inch per month. Follicles determine your hair color. These follicles produce melanin pigments inside them, which determines the hair's color. As we get older, melanin production decreases or stops, resulting in gray hairs.
Hair is very important as it provides warmth, protection, and touch sense. The eyebrows and eyelashes protect the eyes from foreign bodies as well as from sweat. They help to keep the eyes clean from infection by trapping dirt before it can get to them. When the eyelashes sense incoming debris, the eye reflexively closes.
For many of us, it defines who we are. Straight, wavy, curly; red, blonde, brown. No two people have the same hair.