Module: 19 a Close Look at Hair
Module: 19
A close look at hair 219 | P a g e
19.1 The structure of hair The hair is structured in three basic layers: the cuticle, the cortex and the medulla.
The cuticle
If we compare a microscopic view of a shaft of hair to a tree, the outermost layer, called the cuticle, could be compared to the bark. It consists of flat, criss-crossed, horny, dead cells. There are six to ten of these cell layers and they form a structure that looks quite like the outside of a pine cone. The cuticle gives a good indication of the health of the hair. In healthy hair, the cuticle lies flat and so gives a smooth, translucent surface. Light is perfectly reflected, resulting in a healthy shine on the hair. An alkaline environment opens this layer, an acidic environment closes it.
The cortex
This layer is also known as the fiber layer or the trunk. It makes up about 80% of a strand of hair. It’s in this layer that the chemical processes of hair products act. The cortex is composed of bundles of fiber, made up of a large number of very fine keratinous (protein) fibers - the fibrils. They lie along the length of the hair and give it qualities like elasticity and curl. The bundles of fibre are held together by bonds or bridges between the atoms of different chains. These bonds can be of different strengths, resulting in different tensions in the hair. Acting on these bonds is what changes the shape of the hair shaft.
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The medulla
This area of the hair is called the medullary canal or simply the medulla. It could be compared to the marrow inside a bone and doesn’t have any relevance to the professional work of a hair stylist.
The hair root
The bulb shaped root of the hair sits in the hair follicle, which is in the lower part of the skin, the dermis. The texture of the root is softer than the hair shaft. It sits in a matrix of cells called melanocytes. These cells produce pigment and give the hair its structure. The shaft of hair grows upward through the hair follicle to the skin surface.
The chemistry of hair
The components of the hair are mainly the elements carbon (50%), oxygen (23%), nitrogen (17%), hydrogen (6%) and sulphur (4%). Under normal conditions, human hair has a water content of 10%.
The cortex, which is the main part of hair, consists essentially of natural polymers. 90% of the dry weight of hair is from proteins or keratins.
Nutrients for healthy hair
Like all other parts of your body, your hair is dependent on good nutrition to stay healthy and look great. To give it lustrous shine and help it to be strong enough to resist the effects of weather and styling, you need to take care of your hair from the inside by eating a balanced diet of nutritious foods.
As hair is made up almost totally of protein, eating a supply of protein rich foods like chicken, salmon and lean beef will make sure your follicles and scalp have what they need to produce healthy strands of hair. Fish, nuts & seeds provide the Omega 3 fatty acids that are also necessary for great hair. Foods that have the vitamins and minerals hair loves are: eggs, spinach, sweet potato, lentils, berries, yoghurt and oysters.
Other factors also affect the quality of your hair like hormonal changes, quality of sleep and stress. Your hair takes longer than your skin to show the effects of lifestyle and nutrition so allow for this when implementing changes.
Statistics
The individual growth rate and thickness of peoples hair, as well as the number of hair strands, are genetic factors which may be different for each person. Also, the number of hair strands varies according to hair color and type. On average, blonde hair has 150,000 strands, black hair has 110,000, brunette -100,000 and redheads have 75,000 hairs.
Average number of hairs on a head: 0-150,000
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Hair Density: about 200 hairs / cm ²
Daily Hair Loss: about 60-100 strands
Growth rate: about 0.33 mm per day, about 1 cm per month
Hair thickness: 0.04 mm to 0.12 mm
Tensile strength: 200 N / mm ²
Modulus of elasticity: 3000 MPa
Life of the hair follicle: 6-8 years
Hair formation
The type of hair formation - smooth, wavy, curly - depends largely on the shape of the hair, seen in a close up of a cross section of the hair strand. The hair of East Asians has a round cross section, which results in very smooth hair. The European hair type usually has either a round or oval cross-section, so that the hair is either smooth or tends to form curls. In contrast, Africans have hair with a strong, elliptical cross section. This results in hair that forms very strong, small curls.
Hair growth
Hair grows in cycles. A hair follicle goes through several stages, referred to as a hair cycle. Head hair grows between 0.3 to 0.5 mm per day, approximately 15 cm in a year.
The widespread assumption that body hair (facial hair, leg hair) grows faster because of regular shaving is wrong.
How do we go grey? At a younger age, the body produces a lot of melanin, which gives hair its colour. With age, this dye is produced progressively less and new hair is colourless, so to speak. Instead of melanin, the hair stores air bubbles, making it lighter and grey looking. The age at which hair turns grey is individual and depends on genes. Some people are already grey by their thirties, some in their forties, others much later.
19.2 The scalp As a hair stylist, you’ll find most people pay little attention to the scalp. The scalp is one of the very sensitive areas of the body and its condition is critical to the appearance and texture of hair. It also serves to protect the head, regulates water balance and body temperature and is involved in sensory perception. Reasons enough to give to the scalp a little more attention and care!
The scalp nestles like a protective cloak around the head. It is - like all other areas of the skin – made up of several layers which can roughly be described as the upper skin or epidermis, the dermis which sits below this and next, the subcutaneous layers. The subcutaneous layers are
222 | P a g e the bed for hair roots, sebaceous glands and sweat glands, nerves and immune cells. The scalp is a sophisticated system with many functions, such as the exchange of fluids, temperature regulation, sensory perception and protection.
Other components of the scalp are hair follicles, from where hair grows, and sebaceous glands that release sebum. Tallow is what ensures that skin and hair remain supple and gives them shine.
The uppermost layer of the scalp renews itself continuously. While, in deeper skin layers, new keratinised cells are continually being produced, dead horny cells are shed at the skin surface.
If the processes of sebum production, keratinisation and desquamation, or shedding, are out of balance, scalp problems can result such as dehydration, itching, increased flaking or dandruff. It can also affect perception and protection mechanisms.
Functions of the scalp : overview
Protection: By keratinisation and gland secretion, the scalp acts as a protective coat. The layer of hair offers an extra layer of protection. Immune cells that are part of the body’s overall immune system are also located in the scalp.
Temperature regulation: The scalp is able to expand and contract its vessels. With the evaporation of water, the skin on the scalp helps regulate body temperature.
Fluid exchange: The skin on the scalp also controls salts and other fluids, further contributing to temperature regulation.
Sensation: Like the skin in other areas of the body, the scalp contains receptors that serve in sensory perception.
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19.3 A History of Hair
Throughout the ages, how people have worn and treated their hair has undergone much change. Looking at the evolving trends in hair styles and grooming through the centuries is very interesting, particularly over the past century. It’s also fascinating to see how hairstyles, like fashion, can tell the economic and social story of different eras.
What am I worth? Look at my hair!
What was common to all eras was that, like fashion, hair styles represented peoples social status and wealth. Usually, wealthier people choose elaborate styles that needed careful and time consuming grooming which showed their level of personal resources and also defined their position in society. Hair styles also defined different groups in society, lilke religious cults, followers of a particular music genre or pop idol or the military.
Vanity finds ingenious ways to adorn
In ancient society, women in paticular used all kinds of methods to sculpt hair, mostly using natural products like clay or mashed seeds to set styles or crude hot irons to add curls. Styles were dried in the sun.
Hairstyles in Europe from the 16th to 19th centuries became quite ostentatious, especially among the upper classes. At a time when social ranks were much more rigid, this was one way of showing to which level you belonged or aspired to belong. Figures like the royalty set new trends and used less and less hair covering and more decoration, like lace, flowers, jewels, pearls and other decorative objects. Vanity even led both men and women to use products like borax and sulphur which affected their health.
Men wore their hair long or to shoulder length and was also styled and groomed among the upper classes. As well as a social statement on wealth and status, hair that was tied up and groomed was seen as conforming to a moral code. Hair worn loose was confined to the bedroom and if worn down and ungroomed in public would have been seen as immoral or sexual.
20th century hair revolution!
Not long into the 20th century, hairstyles changed drmatically and every decade from then on inspired a new look which often reflected social change. In the 1920s, the bob became all the rage and was part of a revolution in fashion, hairstyles and of womens position in society. New styles reflected womens emerging freedom and independence. The perm was invented - a new ability to permanently curl straight hair. During the 30s hairstyles were longer and softer with waves and styles were lafgely based on what hollywood film stars were wearing.
The 40s and 50s, war and post war years, were less indulgent and more austere and hairstyles were less flamboyant. In the late 50s the beehive style was a big hit, originating in the US, and stayed popular until the mid 60s. During the 60s and 70s pop stars like Elvis Persley and the
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Beatles had a huge influence on society which was ready for major social change and much more freedom, especially for the young. Hairstyles reflected this, imitating the idols who were setting the trends and creating a new atmosphere of expression and a recognised culture for the under 25s for the first time.
The last decades of the 20th century produced more new ideas in hair. The music industry and its stars were firmly established as the major influence on hair trends, particularly among the young. Punk rock stands out as one of the most memorable and new influences, inventing for the first time unattractive, almost menacing looks, worn by a wave of people who clearly did not want to conform to society‘s norms.
Era of the individual
Now, in the era of the individual, the boundaries in society are breaking down more and more and we can see this represented in exterior image once again. Corporate wear has given way to more casual and informal codes of dress and individual expression. For example, for men, formal suits are being replaced with jeans and open necked shirts and hairstyles no longer need to show the control of short, neat cuts to prove one’s merit in the world of business.
The advent of social media means everone now has a powerful voice and the freedom to express themselves how they wish. Physical image has become more important than ever before. Hairstyles and regular grooming has never been so focused on. The demand for creative hair stylists keeps on growing. It’s a career that is full of promise and excitement.
19.4 Different hair types Hair around the world
In general, human hair is divided into three basic types: African, Asian and European. Of course, not all African, Asian or European hair is the same, so this is a very rough classification. Whether the hair grows smooth, wavy or curly depends mainly on the shape of the cross section of the individual strands of hair.
European hair
European hair varies from quite smooth to wavy or curly all over. It is more resistant than African hair and not as stable as Asian hair. Its cross section is round or oval shaped and it has a diameter of about 0.05 to 0.07 millimeters (mm).
The diameter over the entire length of the hair is the same. Light blonde hair is the finest of all. Most blonde hair has on average about 150,000 strands over the head. In Europe you’ll find hair shades from black to red to light blonde. Dark colours are created by the pigment eumelanin. Red and blonde shades of hair are due to the pigment pheomelanin. Northern European hair
225 | P a g e tends to become greasy faster than hair from southern Europe. The reason is the scalp of North Europeans relatively quickly forms a layer of fat because fat protects against cold which is the prevailing climate there.
African Hair
In Africa, you’ll see almost all frizzy, curly or wavy hair. It is a very sensitive type of hair as it is prone to small cracks of different thickness, so it breaks easily. Often, the individual hairs are turned inwards, which is due to the elliptical cross-section. Unlike blondes, dark-haired people have "only" about 110,000 hair strands over the head.
Latino hair
Latino hair is dense, wavy and dark to protect people from heat. Dark hair attracts the sun and thus stimulates the scalp to sweat. This cools the body and protects it from overheating.
Asian Hair
Asian hair has thicker layers than European and African hair. The diameter of an Asian hair strand is between 0.07 and 0.12 mm. Asian hair is more resistant to tearing than European or African hair due to the larger diameter. It has a round cross section and hair is generally smooth.
The colour and structure of hair is defined in each individual’s genes. All hair types have one thing in common: they turn gray with age. At what age we produce gray hair is also genetically determined and related to the natural ageing process.
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Exercises
Exercise 1
Before you start working with real clients you need to practice. There are hairdressing mannequin heads available which allow you to try out all the skills you are learning.
Most mannequin heads are mounted on a special stand so they can be fixed to a table. They are available in different shapes; with long and short hair, with and without a beard and sometimes with real hair. You can find types to practice on every hair style.
It is an extra advantage to practice on a real person, so if you have friends and family who are willing, practice your new skills on them.
Exercise 2. Select the correct answers.
Which of the following foods are nutritious for hair?
Select 7 answers:
Exercise 3. Select the correct answers.
The health of hair is affected by which of the following factors?
Select 4 answers:
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Exercise 4. Answer true or false to the following questions:
True False
- Hair turns grey early or late in life according to how it’s cared for.
If the processes of sebum production are out of balance, scalp problems - can result such as dehydration, itching, increased flaking or dandruff.
- Melanin gives hair shine and suppleness, tallow gives hair its colour
Exercise 5. Select the correct answers.
What kind of figures in society are people most likely to be influenced by when choosing a hairstyle?
Select 3 answers:
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