Hair, is a characteristic of mammalian class of living beings.Hair follicle in the skin is the place where hair grows.
The active living portion of the hair is the follicle. The hair that is visible is the hair shaft. It has no biochemical activity and is non active.  The active portion of the hair is found in the follicle.The base or the bulb contains the cells that produce the hair shaft.  Other structures of the hair follicle include the oil producing sebaceous gland which lubricates the hair and the erector pili muscles, which are responsible for causing hairs to stand-up.  
  The strand of hair is made of the medulla, cortex and the cuticle. The cortex, or middle layer of the hair, is the primary source of mechanical strength. The cortex contains melanin which gives colour to the hair. The colour depends on the number, distribution and the type of melanin granules.
The shape of the follicle determines the shape of the cortex, and the shape of the fiber is related to how straight or curly the hair is. Asian hair typically has a round fiber and is quite straight. Oval and irregularly-shaped fibers are generally more wavy or even curly. The cuticle is the outer covering. Its complex structure slides as the hair swells and is covered with a single molecular layer of lipid that makes the hair repel water.The diameter of human hair varies from 17 to 180 µm (0.00067 to 0.0071 in).
All natural hair colors are the result of two types of hair pigment eumelanin and pheomelanin. Both of these pigments are melanin types, produced inside the hair follicle. Generally, if more melanin is present, the color of the hair is darker; if less melanin is present, the hair is lighter. Levels of melanin can vary over time causing a person’s hair color to change, and it is possible to have hair follicles of more than one color.Eumelanin is the dominant pigment in dark-blond, brown, and black hair, and pheomelanin is dominant in red hair.Blond hair is the result of having little pigmentation in the hair strand.

Gray hair occurs when melanin decreases or disappears.

The hair found on the head serves as primary sources of heat insulation and cooling when sweat evaporates from soaked hair, as well as protection from ultra-violet radiation exposure.The hair on the human body does help to keep the internal temperature regulated. When the body is too cold, the arrector pili muscles attached to hair follicles cause the hair to stand up. These hairs then form a heat-trapping layer above the epidermis. This process is called piloerection. The opposite actions occur when the body is too warm. The arrector muscles make the hair lay flat on the skin which allows heat to leave.
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About Manbir & Gurpreet

Gurpreet Kaur’s journey in this world .... Gurpreet Kaur was a Musician. She was a singer and a composer of music. Her interest was composing and singing Gurbani Shabads in Indian Classical style. She sang Shabads in All the Raags mentioned in Sri Guru Granth Sahib Ji. She also taught Gurmat Sangeet at Gurmat Gian Missionary College, Jawadi, Ludhiana. Elder child to Pushpinder Kaur and Dr. Brig. Harminder Singh, was born in Amritsar on 13th Jan 1962. She attended various convent schools as a child because her father would get frequent Army postings as a dental surgeon. She graduated with Music Honors from Govt. College for Women, Chandigarh. Music was her hobby and she composed and sang Raag based Gurbani Shabads. Doing Kirtan was part of growing up nurtured by her parents. She learned music from her father Dr. Brigadier Harminder Singh who was a dental surgeon in Indian Army and a very good singer himself. Gurpreet’s Bhua (father’s sister), Ajit Kaur retied as a Head of Department of Music from Govt. College for Women Ludhiana, and was a renounced Punjabi singer of her time. Gurpreet Kaur also learned nuances of Indian Classical Music from Pandita Sharma. She was a mother of three children, and a grandmother. Her daughter Keerat Kaur is a Computer Engineer. Her two sons Gurkeerat Singh and Jaskeerat Singh are doctors in USA. Her daughter Keerat Kaur too was part of her group ~ Gurmat Gian Group. Gurpreet Kaur left this world at the age of 54yrs on 12th Sept 2016 in Baltimore USA. She had recorded around 25 cds of Gurbani Keertan. 'Raag Ratan' Album (6 CDs) is a Compilation of Shabads in All the 31 Sudh Raags of Sri Guru Granth Sahib Ji. 'Gauri Sagar' Album (3 CDs) is a Compilation of All forms of Raag Gauri in Sri Guru Granth Sahib Ji. 'Nanak Ki Malhaar' ~ ((3 CDs) is an album of Raag Malhar Shabads in various forms of Malhar. 'Gur Parsaad Basant Bana' ~ (3 CDs) is an album of Shabads in Raag Basant sung in various forms of Raag Basant. Har Ki Vadeyai Sarni Aayea Sewa Priya Kee Preet Piyaree Mohan Ghar Aavho Karo Jodariya Mo Kao Taar Le Raama Taar Le Tere Kavan Kavan Gun Keh Keh Gawan Mera Baid Guru Govinda Saajanrraa Mera Saajanrraa

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