Hair is the most misused, tortured, and taken-for-granted tissue on our entire body. The things we do to it would ruin other parts of the body, but even when damaged and frail, hair keeps growing, unless – of course – you lose it altogether. Hair is a body tissue that grows. It is greatly affected by what we put on it, what we eat, the shape of our mental or physical health, and what we expose it to.
Hair grows from follicles all over the scalp. Hair cells are some of the fastest-growing cells in the body. Each person is born with all the hair follicles they will ever have, about five million of them. The follicle grows from beneath the skin of the scalp and is sometimes referred to as a bulb, because that is what it looks like. Look at a tulip bulb. It is a rounded teardrop shape and usually has several sheaths coming from the small top. That is exactly what a hair follicle looks like.
The shape of the hair follicle determines what kind of hair a person has. Round follicles produce straight hair while oval ones send forth curly hair. If you have round follicles today, it doesn’t necessarily mean you will have them for life. They can change shape throughout your life.
I have a friend who decided to shave her head because her hair had become thin, poker straight, and basically unattractive. When it started to grow back, she started to see a little curl in her otherwise straight hair. It grew in a little thicker and curly. Apparently, her follicles decided to change shape after she shaved her head. This doesn’t happen to everyone.
The follicle is surrounded by two different sheaths. The inner sheath ends below the opening of the oil gland associated with the follicle and the outer sheath grows all the way to the gland. This gland secretes oil and sebum, which serves as a natural conditioner. More sebum is produced as a person goes through puberty, but it starts to taper off as you grow older. These oils keep the hair shiny and healthy; generally, the more you wash your hair, the more oil these glands produce.
The shaft is the visible part of the hair and, believe it or not, it is the dead part of the hair. Yes, our hair is dead. That is why it doesn’t hurt when we cut it. However, this dead tissue has more to it than other dead cells on the body. The shaft has three layers. The cuticle is the colorless overlapping flat cells that give hair smooth or frizzy quality. The cortex determines color and texture, such as curly, thick, thin, or straight hair. The medulla is the heart of the hair that determines its strength.
Hair is a protein made up of Keratin, most of it in the cortex. Blood vessels running through the scalp are what nourish the follicles and help them produce hair, making our hair grow. These blood vessels feed hormones to the hair; as you get older, these hormones change, ultimately resulting in gray hair.
There are three stages to hair growth. Anagen is the growth phase, which lasts for several years. Catagen is a transitional phase where growth slows down and the follicles may shrink in size. Telogen is the resting phase; in many cases the shaft detaches from the follicle at this point and a new hair pushes the old one out. Then it all starts over again.
About 90% of the hair on your head is currently growing while the other 10% is in a resting state. Each follicle produces a new hair about 20 times during the lifespan of a person, assuming they do not go bald. When you see all these statistics, you can truly see how your hair is a wondrous thing and worthy of a great deal of care to keep it healthy.
Bone marrow is the fastest growing tissue in the body, but hair comes in a close second. It takes about three whole years to grow hair out to shoulder-length and seven for it to reach the waist.
The difference between male hair and female hair is infinitesimal; the only difference is that male hair may be a little thicker than female hair. Forensic scientists cannot differentiate gender by hair, but they can find out what a person has put in their body if it ends up in the bloodstream. The most accurate drug screening available is the hair test.
Genes from your ancestors are what give you the type of hair you have. If you have Asian blood, the likelihood of having straight black hair is very great. The odds are much lower if you have German or Scandinavian ancestry where you will be likely to have blond hair. African hair is often curly to frizzy but is very soft; other cultures have curly and frizzy hair that is coarse.
Straight hair includes many different types of straightness including fine, thin, shiny, or coarse. Wavy hair includes types that are thin, fine, or coarse; it can lay close to the head or frizz out toward the ends. Curly hair owns a cuticle that refuses to lay flat. Some hairs curl in an S-shape and others sport a Z-shaped pattern. Hair can tumble down in loose curls, ringlets, and spirals or be tight, coarse, and kinky.
The most common color of natural hair is the dark category. More people existing in the world today have black to brown hair. There are fewer blonds in the world and even fewer redheads. Only one to two percent of all the people in the world have red hair.
It’s a common thing for humans to be discontented with the hair they’ve been given. Many of my friends with curly hair wish they had my straight hair, while there are times, I wish I could coax some curl into mine. We have come up with products that change the color of our hair, alter its texture, and change its curl factor. It is a good thing our hair is dead already because some of the chemicals we inflict on it can be pretty hard on our tresses. Subjecting our hair to the heat of hair dryers, straighteners, and curling irons can damage the hair cuticle as well. If the damage is severe enough, it can cause the hair break off and fall out.