anatomy of a hair

What is Hair Anyway?

Hair—the strands are made of, Medulla (core) Keratin (inner layer) and Cuticle (outer layer).

anatomy of a hair

Each strand of hair has its’ own DNA. There are no two strands alike; and as various and diverse as human beings are, so is your hair—its’ texture, color, and grade.

The Anatomy of Hair

Hair is quite simply defined as a form of a protein called Keratin.

Hair grows from hair follicles located in the dermis~

Dermis= the skin; the thick layer of living tissue below the epidermis that forms the true skin.

Papilla= the structure at the base of the hair follicle; deep at the dermal layer, papilla is also described as a small nipple-like projection at the root of a hair.

Hair Follicles= hair follicles are responsible for the production of hair. They (follicles) produce hair fibers in a regular cycle. Hair follicles, as part of the hair-producing role, retain stem cells, promote cell growth, tissue invasion and induce angiogenesis. Hair follicles also work closely with the immune systems of the skin and neuroendocrine systems.

Hair follicles support immune-surveillance against pathogens and aid in sensory perception. Hair follicles have been proven to metabolically be one of the most rapidly proliferating units of the skin system. Only cells in the stomach proliferate more quickly than hair follicles.

While hair is growing beneath the epidermis, its’ outer covering is soft. Once it goes past the epidermis, the outside layer hardens into keratin.

Inside the follicle, the hair is growing and is ‘connected’ to blood vessels and nerves.

Outside the skin, the hair is essentially DEAD!

Keratin= keratin refers to a family of fibrous structural proteins. Keratin is the key of structural material making up the outer layer of human skin. It is also the key structural component of hair and nails.

Keratin monomers assemble into bundles to form intermediate filaments, which are tough and insoluble and form strong unmineralized tissues.

hair follicle

Hair Composition= hair is primarily made up of protein which occurs as the result of linking together of amino acids. The cortex of the hair is made up of a series of chains that form the shape of a coil.

The amino acid chains coil around each other and become proto-fibrils. The proto-fibrils then twist around each other to become micro-fibrils. Micro-fibrils follow the same process and become macro-fibrils that also spiral together.

This process when complete forms the cortex of the hair. The cortex is then covered with the cuticle scales which also contain protein. This twisting gives hair the ability to stretch like a spring without breaking.

Cortex= the center part of the hair, called the cortex, makes up most of the hair shaft. It is the cortex that gives hair its special qualities such as elasticity and curl. The cortex is packed with strands of keratin (protein), lying along the length of the hair.

All its moisture lays in its center, behind a tough outer layer of protective bark (sort to speak).

If the 'bark' of the hair is well taken care of the whole hair remains in good condition. If the 'bark' is stripped off to expose the center, the hair may break.

Sebaceous Gland= next to each hair is a sebaceous gland that secretes sebum (oily secretion) which lubricates the hair and provides each hair with an element of protection. If the sebaceous glands are overactive, greasy, or oily hair will result. If the glands are under-active dry hair may result including breakage.

For hair that is kinky nappy coily curly (whatever you choose to call it), this Helix spiral (below) resembles its 'curl pattern'

kinky hair spiral           

Parts of the hair

There are three main regions of what makes up an hair: Root, Shaft, and Tip

Root= the part that was growing in the follicle. This is the widest part of the hair.

Shaft= the middle of the length of the hair (from the root to the tip). This is where the hair tapers.

Tip= the end of the hair farthest away from the root. The hair is narrowest at the tip.

Three major layers to the hair

From the outside in cuticle, cortex, and the medulla (middle)

Cuticle= the outermost layer of the hair. It is made of keratin. The cuticle is really a series of overlapping scales- very resistant to chemical decomposition.

Cortex= the intervening layer of the hair (i.e., between the cuticle and the medulla). It is made of spindle-shaped cells and pigment granules (these give color to the hair). You may also find ovoid bodies (look like large pigment granules) and cortical fusi (small bubble-like structures) in the cortex.

Medulla= (from the Latin for ‘marrow’) the innermost layer of the hair. It is made of cells that form a shaft through the middle of the hair. Different amounts of medulla may be present in the hair.

Growth Stages of the hair

3 major growth stages: anagen, catagen, and telogen

Anagen Stage= the active growth phase of the hair follicle.

Catagen Stage= the transition period between growth and rest. Hair continues to grow but at a decreasing rate. The root bulb looks elongated from being pushed out of the follicle.

Telogen Stage= the rest period for the follicle. The current hair is shed and no new growth takes place for a period of time.

So, What is Hair Anyway?

Hair is a fiber that we all have…kinky curly straight. Its function is a protective covering for your head. We can style it, cut it, braid it—the possibilities are numerous.

                  

Some have very dense hair (thick), while others have sparse (not so thick) amounts of hair. Whatever the case, once it hits the surface, it’s dead!

This brings me to my point—the skin called scalp, which houses our hair, is ‘key’ in the ultimate beauty of our hair once it hits the surface.

This means that the decisions we make in terms of the products we use to style our hair, whether that be chemicals like perms and other substances that ‘alter’ the natural texture and structure of your hair—it makes up for the overall health of our scalp and ultimately the look and feel of our hair.

The dermis and epidermis (skin) of the scalp are very porous and the products we use directly of that skin can have a very positive or negative effect on the health of our hair (and general health as well).

Many chemicals, which include perms and color kits have a very adverse effect on the overall health, look and feel of the hair. Many chemicals used in the traditional products that most of us grew up using have ingredients that are known to cause cancer.

We must be mindful and sensitive to ALL products we use—from oils, shampoos, conditioners, gels, sprays, etc. etc. we need to become label readers and commit to only using the most natural and safest products available—this usually means—‘green’ or organic, simple products.

Less is more!

In Conclusion

As people of color, we can celebrate the fact that we have been blessed with a wonderful protectant for our skin called Melanin. Our hair also is a blessing. The coil and bend in your hair act as a wire conductor, storing and transmitting electromagnetic energy!

All energy is in the form of a coil and we have the coil in our hair naturally and innately!

Our hair has the same spiral as an electrical current, tornado, and whirlwinds. All hair has its own DNA! What history!

This special quality allows your hair to absorb light, information, sound, nature, and simple life! This has a positive effect on our ability to be balanced with the universe which is energy itself!

Coily, kinky hair has limited growth potential ONLY when it is not allowed to stay in its natural formation—spiraling coils. If allowed to stay in its natural state, the hair not only grows but exponentially grows beyond your imagination!

We must be re-taught to love our natural beautiful selves and stop trying to be who we’re not.

Once we embrace our cultural identity, we will be able to make a meaningful contribution to ourselves—to love and accept ourselves from head to toe—we then will be able to reach out to our family, community, and others and lift each other up and celebrate our uniqueness with gratitude and thanksgiving!