Chapter 1 Hair Trichology

Hair StructureHair Facts

Human are covered all over with hair, except on the palms of hands, soles and lips. Each person's head, carries about 100,000 - 150,000 hair follicles. Baby's head have 1,100 follicles / sq. cm. By age of 25 numbers gets reduced to 600 follicles. By age of 30 - 50 it reduces to 250 - 300 follicles. Hair characteristics are inherited from our parents.

 Hair Distribution

Vellus : 1 cm long contains no pigments or very little pigment. Follicles producing the do not have sebaceous glands.

Lanugos : It develops on the fetus of 3 months. It sheds off a week before baby is due to be born.They are of same length, all over the body.

Terminal : Long hair present on head and body. They are produced by follicles with sebaceousglands. Gradually these follicles become thinner and shorter in the people prone tobaldness.

Hair Structure

Hair Structure ( Follocle & Cross Section )

Average Hair ( Composed )# Elements Composition (%)1 Carbon 50.65%2 Oxygen 20.85%3 Nitrogen 17.14%4 Hydrogen 6.36%5 Sulphur 5.00%

Composition Of Hair

Hair is composed chiefly of the protein called Keratin which is found in all horny growths including the nails and the skin. The chemical composition of hair varies with its color. Darker hair has more carbon and less oxygen. The reverse is true for lighter hair.

Division Of Hair

Full grown human hair is divided into two principal parts

1. Hair Root Hair root is the part of the hair structure located under the skin surface. This part of the hair is enclosed within the follicle.

2. Hair Shaft Hair shaft is the part of the hair structure the skin surface, extending above the skin surface.

Structure Of Hair Root

Chapter 1 Hair Trichology

The three main structure associated with the hair root

1) The Follicle Structure of Hair Root Follicle is a tube like depression or pocket in the skin or scalp

that encases the hair root. Each hair has its own follicle. The follicle does not run straight down into the skin or scalp but it

is set at an angle. The hair above the surface flows naturally to one side.

This natural flow is called hair stream. One square inch has one Thousand follicles.

2) The Bulb The bulb is a thick ended club shaped structure that forms the

lower part of the hair root. The lower part of the hair bulb is hollowed out to fit over and

cover the hair papilla. 3) The Papilla

The papilla is a· small cone shaped elevation located at the bottom of the hair follicle.

It fits in the hair bulb. Within the hair papilla there is a rich blood and nerve supply.

It is through the papilla that nourishment reaches the hair bulb. As long as papilla is healthy it produces hair cells that enable

grow.

 Layers Of Hair Shaft

The three layers associated with the hair shaft

1) CuticleThe outermost layer is cuticle. It is made of 6-10 overlap piling layer of long cell. The cells lie on the surface as tiles on roof with free edges directed towards the tip. Scales close at scalp are smooth & unbroken, while further down the hair, weathering takes place. It is a protective layer. Shine is due to this layer intact cuticle cells are smooth & glossy & reflect light from their surface cuticle layer is transparent.

2) CortexIt makes most of the hair shaft. It contains granules of melanin.Two types of melanin are there 1) Eumelanin (dark) 2) Pheomelanin (light). In cortex 2 type of bonds are presentDisulphide linkages: Strong bonds. Only break by chemical treatments.Hydrogen Bonds: More in numbers. They are weak bonds. Break even when hair is wet.

3) MedullaGrey hairs have it more.

Wavy hair has it more than straight hair. Vellus hair does not have medulla present.

 Stages Of Hair Growth

Anagen Catagen Telogen

 

Chapter 1 Hair Trichology

Anagen : Hair begin to grow at this stage. Very active growth is there in the hair bulb. This lasts for 2 – 6 years. In older people the hair cycle become shorter, follicles gradually give up producing long, strong hair & the hair become thinner and shorter. The result in thinning of hair and finally may even result in baldness. Melanin is made throughout this phase in bulb.

Catagen : It is the intermediate phase for 2 – 4 weeks. No pigments are made during that time, and the new hair emerges from the same opening at the surface of the skin as the old one, and the hair cycle begins again. The hair length depends on the length of anagen stage, which is genetically determined. As people grow older, the period of anagen shortens. Plucking a hair bring forward the next period of hair growth in that follicle.

Telogen : When catagen phase ends, the hair follicle begins a two six months phase of resting. During teloge the follicle is shorter approximately. One half to a third of the length of the active follicle. A new hair shaft forms and grows alongside the old hair forcing it to fall out.

 Factors Affecting Hair Growth

Anemia slows down the growth. Dieting affects the growth. Zinc deficiency causes thinning of hair and hair loss. Steroids slow down the growth.

Hair Analysis

Porosity : It is the ability of hair to absorb and retain moisture in hair. Types are Good,Moderate and Poor.

Elasticity : It is ability of hair to stretch and return to its original form without breaking. Wethair is more elastic in nature. Both sunlight and chemicals and heat damage

the elasticity.

Moisture Content : More moisture will cause less fly off and hair will collapse. Less moisture willcause more fly off and more volume in hair.

Texture : It depends on diameter. Larger the diameter, Coarser the hair. It depends on the following: Natural hair type, Products being put on the hair.

Stream : The flow direction of hair is called as Stream.

Amount : Approximate number of hair on the scalp.

Types Of Hair

To get the best possible results from your hair care routine. You need to choose the correct shampoo and conditioner for your hair type. How to decide which is your type?

1. Normal Hair

It is neither greasy nor dry It has not been permed, straightened or color treated It holds its style well It looks good and healthy most of the time

You should choose a shampoo and conditioner that are designed for normal hair.

2. Fine / Greasy Hair

It tends to be limp It looks flat and packs volume It is difficult to manage because it does not hold the style It soon gets greasy again after shampooing

Wash hair with good shampoo specially designed for greasy hair and use special conditioner for greasy hair. This

Chapter 1 Hair Trichology

would improve the feel of hair that is greasy at roots and dry at the tips, as well as protecting the hair from damage.

3. Dry Hair

It looks dull It feels rough It tangles easily It is difficult to comb or brush

Use a nourishing shampoo, after shampoo use a good conditioner, deep conditioning is must.

4. Combination Hair

Greasy at the roots Shaft is dry Sometime split ends

Use products that have only a gentle action, try using a shampoo for oily hair and finish by applying a conditioner only from the middle lengths to the end of the hair.

Hair Disorder

Human hair helps to protect the head from the sun and prevents heat loss from the body but otherwise it perform a largely cosmetic function most people take hair for granted, but a loss of excess can give rise to anxieties and often a considerable loss of self-confidence.

1. Canities or whitening hair White Hair

This phenomenon has long been studied but no satisfactory explanation has yet been found however following are the main causes

With age the number of pigment cells in the hair diminishes, thus reducing hair melanin charge.

As one grows older the volume of air in the cortex increases the melanin in the cortical cells.

Severe nervous shock. Severe illness which may cause disturbances affecting the

production and transfer of melanin. Congenital (birth) defects in pigment formation. High temperatures during illness or some infectious diseases.

 2. Dandruff

Dandruff affects over 60% of the population it is usually a mild form of eczema which scales of dead skin flake the scalp. It is sometimes caused by psoriasis a condition in which the skin cells multiply abnormally fast forming larger, thicker or lie as flakes. The best treatment for dandruff to wash hair regularly with a shampoo containing a selenium compound or coal tar extracts. If the problem is severe or persistent one should consult the doctor. Dandruff not only leads to hair loss but may also result in acne and secondary infections of the scalp. The following are the cause which aggravate the condition or may also be indirect causes of the problem:

Poor blood circulation to the scalp Improper diet Unclean habits Use of strong shampoos Insufficient rinsing of hair after washing. As it is infectious it can be caused by using unclean towels, pillow cover, combs, brushes, it can also

be spread from one person to the other

Chapter 1 Hair Trichology

Types Of DandruffPityriasis capities simplex

( Dry Dandruff )Steatoidies

( oily Dandruff )

Cause of Dry Dandruff Poor circulation of blood Improper diet Emotional disturbances Glandular disturbances Uncleanliness Lack of natural oil

Cause for Oily DandruffThis is caused by excessive sebaceous secretions which combine with epithelial scales. This matter being greasy and sticks to the scalp it causes itching, it can because the scales to be torn off the scalp and may result in bleeding. Secondary scalp infections, oily drandruff can trigger off during certain times when sebaceous secretion increase e.g Puberty.

Treatment of Dry Dandruff Herbal shampoo Hot oil therapy Herbal hair tonic

Precaution Gloves should be used while touching the scalp of the person who is having dandruff. Don't use hair chemical very often. One should never sleep with rollers. Never put oil in hair at night Don't take too much oil and spicy food. Take green vegetables and fruits. Take lot of water. Sleep should be adequate.

3. Alopecia

Alopecia is the most common complaint found especially in men. Men start the complaint with a receding forehead whereas women start thinning of hair in partial area. Normal hair fall should not be confused with excessive fall. If women complain of finding hair on her pillow in the morning and the loss is more in front and top she is heading for the type of alopecia.

Alopecia TotalisThis

condition is rare and is characterized by total loss of hair all over the body. The cause is not known and is believed to be metabolic.

Alopecia Senilis Loss of hair in old age the loss is permanent and sets in gradually.

Alopecia PrematureThis form of baldness occurs before the age of forty. It starts with an extra oily scalp. The thinning is more in front and top. The cause is believed to be hormonal, humid climate, spicy food.

Alopecia Areata It is sudden falling of hair in round patches in various size starting from ½ inch to 3 inch. The area of hair loss is slightly depressed, smooth, pale compared to the rest of the scalp. The cause is not exactly known but is believed to be of

Chapter 1 Hair Trichology

nervous origin leading to lack of blood supply to the area. Sometime anemia, typhoid, influenza and nervous shocks may result in Alopecia Areata.

4. Split ends

Split ends always occur on dry hair due to lack of sebum

Split End – Causes Split End - Treatment1. Too much use of chemical2. Too much exposure to the sun3. Blow dry at the ends.4. Excessive use of thermal pressing and crimper.5. Regular Trimming is not done.6. Excessive back combing.

1. Cut the split ends immediately2. Deep conditioning twice in a week.3. Application of henna with lots of Fenugreek Seeds.4. Trimming of the hair on regular basis.

Chapter 1 Hair Trichology

5. Other Forms of hair loss

Certain types of hair styles such as tight plaits and ponytail may lead to loss of hair in the front hair line, known as traction alopecia.

Application of rollers with heat when the hair is pulled excessively leads to breakage and damage of hair. Chemical Treatments Blow Drying of dripping wet hair can cause damage and risk to the hair.

Hair Disorder Treatment 

Hot oil therapy High protein diet with supplement of iron and vitamin Proper cleanliness of scalp The hair should be dried thoroughly, with a towel. Brushing or combing twice a day. Avoid making tightly pulled back ponytails.

 Ph scale

PH means Potential Hydrogen, the amount of hydrogen in any solution determines whether it is more alkaline or more acidic. The product that is more acidic can have PH ration 0 to 6.9. PH ratio 7 to 14 more alkaline. Higher Alkaline product can lead the hair to be dry and brittle.

PH Scale at the center is 7 which is neither alkaline nor acidic, it is neutral base. Any solution if it is more than 7 it is harmful, if it is less than 7 it is less harmful.