Raw elements and proteins make up the majority of your hair’s composition. Protein is made up of amino acids, which are organic compounds composed of the COHNS (Carbon, Hydrogen, Nitrogen, and Sulfur) elements. A long chain of these molecules forms a polypeptide chain, which moves in a spiral fashion. If you’ve been wondering whether your hair is healthy or not, take a look at these tips for preventing hair damage.
To feel the cuticle, pinch a single long hair between your fingers. Run your fingers along the outer layer of the hair, starting at the tip. If you feel the cuticle, it will resemble a telephone cord, which makes it elastic. The cortex is stuffed with pigments, which are tucked away within the cells. Because hair is so elastic, it releases and straightens with slight pressure. This is what gives hair its color.
Depending on the part of the body the hair grows on, human hair performs many functions. The hair on the head protects the skull from the sun and dust, while the hair on the eyelids prevents particles from entering the eye. Eyebrow hair also protects the eye from dust and sweat, and is a major part of non-verbal communication. The whisker-like hairs are also sensory, acting as tactile sensors. If damaged, hair will regenerate without scarring.
Human hair grows from follicles, which are tubes-like structures in the skin and scalp. The hair stems from the cells of the dermis and is composed of keratin and related proteins. Hair cells begin dividing in the follicle, which is a tube-like pocket of the epidermis. A small portion of the dermis lies at the base of the follicle. These cells are responsible for the production of the hair shaft and are surrounded by pores.
Human hair has a long history. Its origins are unknown, but hairs have served multiple functions for humans. During early modern times, it was the hair of Manchus from central Manchuria and Han Chinese during the Qing dynasty. Men with this hairstyle shaved their head every ten days to simulate male-pattern baldness. Their hair was then braided into a long pigtail.
The composition of human hair is largely determined by genetic factors. Interestingly, different genetic factors contribute to different hair thickness and texture in different ethnic groups. The innermost layer is made up of amino acids, carbohydrates, and glycogen, while the middle layer is made up of keratin bonds and melanocytes, which produce the pigment melanin. The outermost layer is called the cuticle, which is composed of lipids and repels water.
Humans have approximately 5 million hair follicles on their bodies. On the scalp, there are around 100,000. This equates to about 300-500 hair shafts per square centimeter. Each follicle can grow as many as 20 individual hairs in its lifetime. Hair density and color are closely related. Caucasians have the densest hair while Africans have the thinnest and slowest-growing hair. A man’s natural hair color also affects hair density.