Home Hair Care Basics Anatomy of Hair
Anatomy of HairHuman hair is a filamentous outgrowth of the skin. It grows from hair follicles deep in the skin dermis and projects out above the epidermis. As per its localization, human hair is called body hair, head hair, armpit hair, pubic hair, etc.
Hair provides insulation from the heat/cold, protection against abrasion, and shows sexual distinction. With a range of pigments, it adds beauty and variety to the human body.
Generally humans have long hair on the head and shorter hair on the eyelids and eyebrows. Armpit hair and pubic hair serves as lubrication during rubbing. Broadly, the structure of hair is divided into two components: the hair root and hair shaft. The main building block of hair is α-keratin, a kind of protein.
The Hair RootSimilar to the root of a plant, the hair root is an elongated strand below the skin surface. It originates from a tube like structure called the hair follicle. New cells are created in the hair root, they are pushed up and out, causing visible hair growth. But the hair you see is actually a dead tissue, in this respect hair is quite similar to the finger nails.
Fed with blood streams the dermal papilla carries nutrition to the hair follicle. It is also the receptor for male hormones and androgens.
The Hair ShaftThe hair shaft is formed from the old cells that are pushed out as new cells grow from the root.
By understanding the components of hair and their functions, you can treat your hair better.
The cross-section of hair is divided into three parts: the cuticle, the cortex and the core.
Cuticle is the outermost layer of hair. It is made up of hard, transparent cells that overlap each other like the scales of a fish. The general hair condition is largely determined by the condition of the cuticle as it gives elasticity and resilience to the hair.
Cortex forms the middle layer. It is protected by cuticle and consists of protein fibers. When the cuticle is damaged the cortex becomes weak and unraveled causing split-ends and damaged hair.
It forms the core and is the supporting structure for a strand of hair. In some cases a medulla can be absent or interrupted without weakening the hair strand.