The hair shaft is what is grows out of the hair follicle and is what we consider to be hair. It has three parts; the cuticle, cortex and medulla.
The outer layer of your hair shaft is called the cuticle, which holds your hair together. The cells or scales that make up the cuticle layer overlap similarly to the scales on a fish or the shingles on a roof. In healthy hair, the cuticle scales lay flat. In damaged hair, the scales may be missing or broken. (
The cuticle layer is your hair's armor; it protects the heart, or the cortex, the layer beneath the cuticle. It is made of long, molecular chains of amino acids (protein) and is the largest section of your hair.
Chemical straighteners must penetrate through the cuticle to access the cortex, where shape and color changes take place.
Hair is made of dead keratin (protein) cells that are pushed up through the scalp at an average rate of about one-half inch per month for six inches of hair growth each year.
Keep your hair healthy by eating well, frequent conditioning and gentle treatment.
About The Author
Nicole Elizabeth Smith, the author of "Healthy Black Hair" (2003), is a freelance health and beauty writer and a graduate of Michigan State University. She and her son Zack live in Michigan. Currently, she is beauty editor for .