The Scientific study of hair

Note: “The information you are reading is backed by the official text book of the state board of cosmetology”

My Crown and glory...
Curly hair has been through so many challenges it's amazing to see how far we've come.  It's interesting because I've been through cosmetology school twice, 1992 and again in 2014.  Both times they didn't teach much about curly or afro hair.  Yes, they mention its existence but nothing in depth.  Sadly that's because the educators knew nothing about it.


Around 2012 is when people started going natural and it forced the hair industry to focus on the people's needs.  It's funny how we are the driving force behind many changes.  Black hair is the 1# highest selling market in the hair business.  We the people forced the change.  Clients were popping up everywhere asking to go natural which forced the hairstylist to learn to satisfy the clients.  Now, here we are today!  
Hair is one of the most important attractions for people all over the world.  In different cultures, hair defines beauty, status, and spiritual strength. It plays a big part in how people were valued and how they appreciate themselves.


Many cultures view hair in different ways.  Some believe that it’s a spiritual gift that functions as a message directly to the higher source.  In ancient days, people from different cultures did not believe in cutting their hair.  To them, i represented lack of strength.  It was also a symbol of slavery or being conquered or enslaved.

Again today, people recognize hair as a symbol of beauty.  Not only did we change to natural, but many people have become health conscience.  It's a blessing to see how far we've come.



• It’s important to get to know an essential part of your body that has been altered for so long.


• You must know why hair grows and why it falls out, and to learn the difference between normal and abnormal hair condition and how to heal it. 


• You must learn to recognize an unhealthy scalp condition that can harbor a contagious disease or even cause permanent hair loss and ways to care for your scalp and hair’s wellbeing.  



The scientific study of hair, its diseases and care are called trichology (trih- KAHL-uh-jee, which comes from the Greek word trichos (hair) and ology (the study of).


A mature strand of human hair is divided into two parts;
The hair root;  The hair root is the part of the hair located below the surface of the epidermis (the outer layer of the skin). It’s like a plant’s root that grows underneath the soil.
The hair shaft; The hair shaft is the portion of the hair that shows the epidermis, (Scalp), like the plant’s stem that grows above the soil.


The five main structure of the hair root including the hair follicle, hair bulb, dermal papilla, arrect pili muscle, and sebaceous (oil) glands.


(HAYR FAWL-ih-kul) is a protective tube or pocket that grows around the hairroot and protects it.   


We’ve got hair follicles all over our body except for the palm of the hands and the soles of the feet.  The follicles extend downwards from the epidermis ( theouter layer of skin) to the dermis (the inner layer of skin), where it surroundsthe dermal papilla (a small cone shape at the follicle base).  Sometimes a bunch of hair can grow from one single follicle.


Curly hair follicles are shaped differently than straight and wavy hair.Depending on the waves, curls and coils..it’s adopts the different shapes.The flatter the oval is, the curlier the hair will be.

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Hair bulb
 (HAYR BULB) Is the lowest part of the hair strand.  It is the thickened bulb (club) structure that forms the lower part of the root.  The lower part of the hair bulb fits over the dermal papilla and covers it.   
The dermal papilla 
(plural: dermal papillae) is a small, cone-shaped elevation located at the base of the hair follicle that fits into the hair bulb  “Check out the diagram above.”
The dermal papilla contains the nerves and the blood.  Some people refer to the dermal papilla as the mother of the hair because it provides the nutrients needed for the hair growth.

The arrector pili 
The arrector pili muscle is a small involuntary muscle in the base of the hair follicle. Intense emotions of cold sensations cause it to contract, which makes the hair stand straight up and results in what we call goosebumps.
The Sebaceous glands 
The sebaceous glands are the oil glands in the skin that are connected to the hair follicles.  The sebaceous glands secrete a fatty or oily substance called sebum.  Sebum lubricates the scalp.  It’s our natural oils, and it’s essential to
the skin and hair.


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The three main layers of the hair shaft are the hair cuticle, cortex, and medulla.

The hair cuticle(HAYR_KYOO-ti-kul)
It's the outermost layer of the hair.  It consists of a single overlapping layer of transparent, scale-like cells that look like shingles on the rooftop.  The cuticle layer provides a shield that protects the inner structure of the hair as it lies tightly against the cortex.  It is responsible for creating the shine and the 
smooth, silky feel of healthy hair. And even though all of the cuticles overlap, each individual one is attached to the cortex.  Each overlapping scale makes up the cuticle layer.


Putting solutions like hair color swells and raises the cuticle layer and opens space between the scales, which allow liquid to get inside the cortex.  

Try this:

To feel your cuticle, grab a strand of hair near the root (scalp) then glide your fingers from the scalp up to the ends.  The strand should feel sleek and smooth.  Now take the same strand of hair and start from the ends and slide
down toward the scalp in the opposite direction and explore the cuticles rising.


That’s because you’re going against the natural flow.  A healthy compact cuticle layer is the hair’s primary defense against damage.
The cortex (KOR-teks)
is the middle layer of the hair right beneath the cuticle.   It’s a fibrous (fiber) protein core formed by elongated cells containing melanin pigment.  About 90% of the total weight of hair comes from the cortex.  The elasticity of the hair and its natural color are the results of the unique protein structures located within the cortex.  Anything that has to do with coloring, wet sets, heat, perms, and relaxing takes place within the cortex.  
The medulla (muh-DUH-uh)
The medulla is the inner layer of the hair and is composed of round cells called melanin within the elongated cells.  Very fine and naturally blond hair to entirely lack a medulla.  Generally, only thick, coarse hair and all male beards contain a medulla.