Ideals of beauty have always laid great importance on hair. Indeed, the look of the hair and the way it is worn makes a great deal of difference to one’s appearance. Down the ages, thick, long, lustrous hair is the main beauty assets.
Ancient records contain details of treatments with oils, lotions, infusions and pastes for the beauty and health of the hair. Hair was even known to be perfumed by being exposed to smoke from incense.
The emphasis on hair as a beauty asset decrease with time. In fact, products for hair care, probably record the highest sales among cosmetic items. Both men and women are most concerned about their hair and problems associated with it cause much anguish and despair.
Before puberty the hair is mainly present on the scalp. At puberty hair grows in other places like, axillae, over the pubes in both sexes and in male as beard on the face.
Hairs can be found nearly all over the surface of the skin except over some specific sites like the sides and soles of the feet, the palms of the hands, the lips, and portions of the external genitalia.
All of us, therefore, agree that healthy hair is basic to good looks. The good condition of hair is imperative, not only for one’s appearance, but as a means of keeping hair problems at bay.
Yet, we see a great deal of hair damage caused by neglect and abuse. Hair damage, in turn, can lead to hair loss. Damaged hair is in a delicate state and tends to fall, or break off, easily.
So, we really owe it to ourselves to give hair the treatment. It deserves and for this, it is essential to have some knowledge about hair. How it grows and the factors that can cause damage. We also need to know how to protect it and restore its good health and beauty.
A) Hair Structure:-
1) Hair And Hair Follicle:
- Hair production is a process of mutual involvement of both dermis and epidermis and originates from hair follicles. Hair follicles extend deep into the dermis. Typically, projecting into the underlying subcutaneous layer.
- The base of the hair follicle, called hair papilla, is a peg of connective tissue containing capillaries and nerves. Hair papilla is further surrounded by hair bulb which consists of epithelial cells.
- Hair production is a specialized cornification process. The epithelial layer involved in hair production is called the hair matrix.
- Basal cells near the center of the hair matrix divide by mitosis producing daughter cells and are gradually pushed towards the surface.
- The new soft cells are funnelled up through the constricted follicle. The cells produced closest to the center of the matrix form the medulla or core of the hair.
- Cells closer to the edge of the developing hair form the cortex which is relatively hard. Soft and flexible keratin is present in the medulla, but the cortex contains hard keratin which gives the hair its stiffness.
- Coat of the hair is called cuticle which is formed by the dead cells at the surface of the hair. Hence, it contains hard keratin.
- Hair is completely consist of a protein matter called keratin. Each hair grows out of a sac-like cavity called the hair follicle, which lies below the surface of the skin.
- The root of the hair is extended from the hair bulb to the point about halfway to the skin surface where internal organization of the hair is complete.
- The follicle contains the hair root, while the part of the hair that we see is the hair shaft. The thickness of the hair is determine by the hair follicle.
- The texture and color of the hair is mainly determine by heredity and radicle characteristics. The hair shaft, or keratinous matter, that we see, is actually dead.
2) Hair Nutrients:-
- The hair follicle is fed by the blood flowing to it. That is why nutrition plays an important role in the health of the hair.
- The nutrients in the blood are transports to the hair follicle. Deficiencies in the diet means inadequate supply of nutrients to the follicle.
3) Hair Composition:-
- Each hair is consist of three concentric layers. It has a central core called the medulla.
- Surrounding the medulla is the cortex and the outermost layer is the cuticle.
- The cuticle is consist of tiny scales which overlap each other.
- It is the good condition of the cuticle which contributes to the shine and smoothness of the hair shaft.
- The damage hair, the cuticle may strip off in an uneven manner, making the hair dull and rough.
4) Sebaceous Gland:-
- Sebaceous glands are attach to the hair follicles that secrets sebum. The natural oil of the skin and scalp.
- Sebum get distribute all along the hair shaft and also contribute into the luster and health of the hair.
- In fact, the health and look of the hair depends on the proper distribution of sebum along the entire length of the hair shaft.
- Under activity of the oil glands, or a scalp condition like dandruff, can interfere with the free flow of oil along the hair shaft.
- It giving rise to a dry hair condition, or a mixed hair condition, where the ends are dry, but the part near the scalp is oily.
You can also read about Skin: Structure, Function, And Skin Types
5) Hair Cycle:-
- Hair grows in phases and has a life cycle that can last from a few years to a few months.
- It depends upon the various factors like age, hormonal changes and the general condition of the hair.
- Each hair goes through the anagen, or growing phase, followed by the telogen or resting phase.
- Finally, the hair falls out is replace by another. This is the catagen phase.
- Some of the hair on your head falls daily and a new hair grows in its place. This is a natural process.
- In fact, we hardly notice it. The normal hair fall is about 100 every day.
- However, it is when the rate of hair fall overtakes the rate of replacement that we face the problem of thinning hair, or hair loss.
B) Function Of Hair:-
- The hair on the head protect the scalp form ultraviolet light, cushion round the head, and insulate the skull.
- Eyebrows protect the eye form small foreign particles and insects, also it diverts sweat from the eyes.
- Vibrissae, the hairs, guarding the entrances to nostrils and external car canals filter the air and help prevent the entry of small insect and foreign particles.
- Body hair helps in evaporation of perspiration and draining of external water from the body.
- Hair is also part of sensing function. As, to check a root hair plexus of sensory nerves surrounds the base of each hair plexus of sensory nerves surrounds the base of each hair follicle, one can fell the movement of the shaft of even a single hair, this sensitivity acts as an early-warning system hat may help to prevent injury.
It is responsive to several external stimulating conditions like rage, fear cold etc. and stands erect when stimulated erector pili pull on the follicles and force the hairs to stand erect.
C) Hair type:-
The hair type helps in deciding on the kind of products should be use and the methods of hair care that should be follow
1) Normal Hairs:-
- If your hair naturally lustrous and easy to manage, it falls in the category of normal hair.
- The oil glands are producing the amount of oil that your need for the health of the hair.
- The distribution and flow of oil along the hair shaft is normal, keeping the hair free of problems.
- This , however, does not mean that your hair does not require regular care.
- There are several factors that can upset the normal balance of the scalp, like exposure to the sun, air pollutants, permanent wave lotions, sprays, dyes, chemical colorants or illness.
- Therefore, regular care of normal hair is very important.
2) Dry Hairs:-
- If your hair is difficult to manage and has the ‘fly away’ look, you probably have dry hair.
- The oil glands are not secreting enough natural oil, or the hair has suffered damage from chemical treatments and exposure to the elements.
- Hence, dry hair looks dull and acquires split ends easily. It may also be brittle and break off easily.
- Sometimes, the use of wrong shampoos can cause dryness. So, also can a bad case of dandruff.
3) Oily Hairs:-
- If you have an oily skin, the chances are that your hair is oily too.
- The sebaceous glands are over active and are producing excessive oil.
- Your hair looks good when you shampoo, but becomes limp soon after.
4) Mixed Condition Hairs:-
- This kind of hairs usually has poor distribution of oil along the hair shaft.
- The scalp may be oily, but the hair is dry.
- There may be dandruff, with the scales clogging the pores of the scalp.