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Hair Make by biological

Monday, April 9, 2012 Leave a Comment

               The hair and scalp are two such delicately linked and intricate subjects that one can understand why countless generations before us have preferred to remain in blissful ignorance of them But whether we like it or not , First impression are formed on appearances and our hair is very often the first part of us to be noticed . Hair care plays a more prominent part in beauty routines now than ever before , yet it still often neglected - simply because it least understood . So what exactly is hair and how is it formed ?

Root of the hair
Root of the hair 
        
               Hair is a slender , thread-like extension on the skin . There are between 80,000 and 150,000 hairs on the human head at any one time , depending on gender and hair color . A natural blonde tends to have more hairs on the scalp than a redhead and women tend to have more than men . But all of these hairs , or at least those which are visible to the human eye , are dead; it is from a root deep beneath the scalp , or the papilla , that life goes on .



Hair scalp structure
Three layer of the scalp
                 The scalp is made up of three layers ; the epidermis , the dermis ,and the hypodermis . The epidermis , more commonly known as skin , it follow a life cycle which is completed between five and six weeks and itself divided up into layers . The epidermis is fed by the dermis layer , which is the main place of the hair follicle where the hair get a actual life . The dermis is the base of the follicle where the papilla is found and where the hair cells are produced .Living cells need nutrition and our hair cells draw their from blood vessels , which also feed the sebaceous glands with sulphur . The sebaceous glands are attached to the hair follicle and produce sebum which lubricates the hair shaft and scalp . For some people sebum is automatically associated with oiliness and is a dirty word , but it is vital to the well-being of our hair because it seals in essential moisture which protects it from dangerous elements such as the sun , wind and weather ; it also contains a natural antiseptic which helps fight infection . Sulphur supplied by the blood vessels controls the flow of sebum . The dermis also  contain the nerves and nerve cells which are sensitive to touch , heat and movement . The third layer of the scalp , the hypodermis  is situated at the base of the dermis and is make up of fatty acids present in sebum .

The hair itself or hair shaft is also divided into three layers . Such as :
                                                                                                             1. Cuticle
                                                                                                             2. Cortex 

                                                                                                             3. Medulla

                  1. Cuticle :
            
                  The cuticle is the outer layer of the hair and its protective coating . Believe it or not , The cuticle is also the made up of the layers , but in this case they are layers of overlapping transparent scales of keratin , which is a hard protective protein also found in the nails on the hands and feet . When the hair is wet these scales open out and when it is dry they close . Beautiful shiny hair is the result of the cuticles lying smoothly on the surface of the hair shaft where they reflect the light .Dull hair is the product of damaged cuticles which cannot lie flat or catch the light . This kind of hair becomes porous , Which means it absorbs water and other substances at different rates along its lengths . A figure have given below : -


Cuticle

                     2.Cortex :

                     The second layer of the hair shaft , the cortex , is the main bulk of the hair and contains the hair pigment granules which gives the hair its color .




Cuticle Cortex Medulla
Cuticle , Cortex , Medulla


                    3.Medulla :

                    The medulla is not always present in the hair shaft  , but when it is there it is located in the center and is made up of soft fibrous keratin .



Next Point step by step : How does Hair grow ?

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