Hair Structure

The route to Understanding how to take care of YOUR hair, is to grasp a basic understanding of the structure of your hair . Understand what benefits or non-benefits that products have on your hair. Understand the benefit of your eating habits on your hair..What are you feeding you hair?

There are four parts of the hair: the follicle, the cuticle, the cortex and the medulla. On average, each hair strand grows about six inches per year and then dies, usually before four years.

Follicle

The follicle is the portion of a strand of hair below the level of the skin. This is where hair begins and where it receives the nutrients it needs to grow and survive. The arrector pili and the sebaceous gland are considered part of the hair follicle, they are small muscle fibers attached to each hair follicle. They cause hair to stand up by contracting.  they contract involuntarily in cold weather, causing “goose bumps.”
The sebaceous gland delivers sebum to the follicle. Sebum is a greasy substance that lubricates hair and keeps it soft.

                                                                                   

Above scalp level, hair strands have three layers: the cuticle on the outside, then the cortex, and the medulla on the inside. Unlike the structures below the scalp, these are keratinized, or hardened and non-living.






Cuticle 
The cuticle surrounds a strand of hair, it acts like a roof. It determines how hair reflects light, its sheen. It consists of scales that grow and point towards the tip of the hair, sometimes five to twelve layers deep. The cuticle is translucent; even though it is on the outside, it is not the source of hair color.  It blocks moisture from leaving the hair shaft. It also slows down entry of substances (water/oils/conditioning agents) and it protects the shaft from damage The cuticle protects the cortex inside.


Cortex
Inside the cuticle is the cortex which is responsible for most of the hair’s width, weight and visual properties. It is composed of braided fibers with pigments of brown, black, yellow and red. The ratio of these pigments determines hair color. The cuticle is also responsible for whether hair is straight or curly, tough or weak, thick or thin. The cuticle is made mostly from protein and water.

Medulla
Inside the cortex of some hairs is a medullary canal. This canal contains only air and seems to have little or no effect on the properties of a strand of human hair.



HHJ- Ladyno