What is hair?
Scientifically speaking, hair is protein. Keratin protein to be exact. It's the same material for all people.
That doesn't explain a lot, I know...and is probably more confusing when you think about how different everyone's hair looks, but we'll get into that. We're starting from the ground up.
The strand of hair is comprised of three things. The medulla, the cortex and the cuticle.
These three components are what makes hair, hair. However, not everyone has a medulla. Science isn't exactly sure why this is, but medullas are typically found in afro-ethnic hair and some Asian hair. The theory behind this is that hair can be like a fiber optic cable for some people, in that UV light can pass through the hair shaft. Some scientists believe that in these cultures (where the people historically spend a lot of time in the sun...ie: tribesman) the medulla was necessary to prevent UV light from passing into the scalp and causing severe damage to the head, like skin cancer. However, this is just a theory. Either way, we're not exactly sure why some ethnicities have them and others do not, but they may have something to do with the texture of ones hair also (like, how tightly wound the hair is upon itself in relation to the tightness of a curl).
The cortex is where the pigment is found. Natural pigments are called melanin, and all natural hair colors are made up of eumelanin (black) and pheomelanin (red) in various combinations. The cortex is also the part of the hair that determines the shape of the hair. When we curl or straighten our hair, this is the part of our hair that is being affected.
The cuticle is the outermost layer that protects the cortex and medulla. It's similar to shingles or pinecones, with overlapping layers to wick moisture away. The cuticle can also open and close, though opening it is almost always against its will, and what we "see" when we see damaged hair. When we see frizzy hair, what we're seeing most often is hair whose cuticle has been damaged and remains open in places, resulting in inconsistent porosity (how much moisture the hair absorbs and retains) and elasticity (how much the hair can stretch and return back to normal) from root to ends.
So it's actually pretty simple here...the basics on what hair is. It's keratin protein that makes up 2 to 3 parts of a hair strand with some melanin thrown in. The combinations of melanin, or thickness of the components are what makes all of our hair so different...the basic level is all the same.
Next article B2B 1.2 - How does hair grow?
