Hair 101: Hair Basics (Know Your Locks!)

Do you know what hair is? How it grows? What gives it color? Why it’s straight or curly? Today we’re going to cover a little Hair 101: Hair Basics–Know Your Locks! Whether you’re a hair expert or a complete novice, read on for everything you need to know about this essential part of our bodies!

Humans have two types of hair called terminal hair and vellus hair. Terminal hair is the type of hair that is on your head, eyebrows, eyelashes, and pubic region. Vellus hair is the soft, downy hair that is on the rest of your body.

Basic Hair Structure

The Follicle

Each strand of hair grows out of a tiny hole in the skin called a follicle. The follicle is like a tiny pocket that is made up of cells. The cells at the bottom of the follicle are alive, but the cells at the top of the follicle and beyond are dead. This is why haircuts and chemicals don’t cause us pain. 

The follicle is also where the hair’s color comes from. The follicle contains tiny tubes called melanocytes. These tubes produce a pigment called melanin, which gives hair its color.

Also attached to the hair follicle is a sebaceous gland. This is a tiny gland that produces sebum, an oily substance that lubricates and waterproofs the hair shaft. Sebum also helps to keep the scalp healthy by preventing the growth of bacteria and fungi. Too much sebum can lead to oily hair, while too little can result in dry, brittle hair.

The average person has about 100,000 hair follicles on their head!

The Shaft and the Root

Hair has two main parts. The shaft is the part of the hair that you can see. It’s made up of dead cells that are filled with a protein called keratin. The shaft is attached to the root, which is the part of the hair that’s under the skin. The root is within the follicle, which goes deeper in the skin. The follicle is where the hair grows from.

A muscle is also attached to the root, which is what makes it possible for us to move our hair. The muscle is called the arrector pili, and when it contracts, it makes the hair stand up. This is how we get goosebumps!

Anatomy of a Hair Shaft

If you looked at the end of a cut strand of hair, a cross section, you would see that there are two or three layers: the cuticle, the cortex, and, in some cases, the medulla.

• The cuticle is the outermost layer of the hair shaft. It is made up of dead cells that overlap each other like shingles on a roof. The cuticle protects the inner layers of the hair shaft from damage.
• The cortex is the middle layer of the hair shaft. It is made up of long, protein fibers that give the hair its strength.
• The medulla is the innermost layer of the hair shaft. The medulla is most commonly found in thicker hair. It is made up of transparent cells and is filled with air.

How Does Hair Grow?

Hair growth is centered in the follicle. Hair is made of a tough protein called keratin. It’s produced in the hair follicles. Hair grows from the bottom of the follicle (the root.) The root is where blood vessels deliver nutrients and oxygen that are needed for hair growth. As the follicle produces new keratin cells, they push older cells up the shaft of the hair. This is why hair grows from the root to the tip.

Growth Phases

There are three phases of hair growth: the anagen phase, the catagen phase, and the telogen phase. Hair grows in cycles. The first phase, called the anagen phase, lasts 1-7 years, though the average is about three years. This is the phase when the hair follicle is actively growing new hair. The second phase, called the catagen phase, is the time when the hair follicle begins to shrink. This second phase lasts about two weeks. The final phase is the telogen phase, which is when the hair follicle rests and the old hair shaft falls out.. This final phase lasts about three months. After the telogen phase, the hair follicle will begin to grow new hair and the cycle starts over.

Hair Color and Texture

The color of our hair is determined by the amount and type of pigment in the cells. Melanin is the pigment that gives our skin and hair its color. People with more melanin will have darker skin and hair, while people with less melanin will have lighter skin and hair.

The shape of our hair follicles is what makes our hair straight or curly. Hair follicles have been described as being oval or round-shaped. Oval-shaped follicles produce straighter hair, while what was thought of as round-shaped follicles produce curly hair. A study from 2017 determined that what was once thought of as “round” follicles are actually S-shaped, having 2 curves. The degree of the curve determines whether someone has wavy, curly, kinky, or coily hair.

The shape of your hair follicle is determined by your genes. If you have straight hair, it’s because you inherited the gene for straight hair from your parents. If you have curly hair, it’s because you inherited the gene for curly hair from your parents. It’s that simple!

The size of your hair follicle also affects the texture of your hair. If you have large hair follicles, your hair will be coarse. If you have small hair follicles, your hair will be fine.

The thickness of your hair shaft is also determined by your genes. If you have thick hair, you inherited the gene for thick hair from your parents. If you have thin hair, you inherited the gene for thin hair from your parents.

Now that we know the basics of hair, let’s talk about how to take care of it! Hair is actually quite strong and resilient. However, it is still important to treat it with care. Here are some tips for keeping your hair healthy and looking its best:

• Wash your hair regularly with a quality shampoo free of sulfates, parabens, DMDM (releases formaldehyde) Phthalates and alcohols.
• Don’t wash your hair every day. Over washing can strip the natural oils from your hair, leaving it dry and brittle.
• Use conditioner properly after every wash. This will help keep your hair hydrated and prevent tangles.
• Protect your hair from heat. Limit your use of styling tools if you can, but if you do use them, make sure to use a heat protectant spray beforehand.
• Brush your hair gently, starting from the bottom and working your way up.
• Get regular trims to keep split ends under control.

We hope this article has given you a basic understanding of hair: what it is, how it grows, and how to take care of it. The experts at Elan are always happy to help you with your hair care choices. Stop by and see us today!