Saturday, August 1, 2009

What is human hair made of?

a chemical called keratin



What is human hair made of?

im pretty sure that its dead skin cells



What is human hair made of?

Hair cells



What is human hair made of?

It is made from nothing its natural.



What is human hair made of?

Hair, collective term for slender, threadlike outgrowths of the epidermis of mammals, forming a characteristic body covering. No animals other than mammals have true hair, and all mammals have hair. Even such apparently hairless mammals as the rhinoceros, elephant, and armadillo have hairs around the snout, at the tip of the tail, and behind each scale, respectively. (Whales and manatees have hair only in the embryonic state.) When the individual hairs are fine and closely spaced, the coat of hair is called fur; when soft, kinked, and matted together, the coat is called wool. Coarse, stiff hairs are called bristles. When bristles are also pointed, as in the hedgehog and porcupine, they are called spines or quills.



Individual hairs are composed chiefly of the horny scleroprotein known as keratin and contain neither blood vessels nor nerves. They usually contain pigment (except in the case of albinos), and sometimes they also contain interstitial air bubbles that give the hair a silvery color. The shaft of the hair consists of modified epithelial cells arranged in columns surrounding a central medulla (or core) and covered with thin, flat scales. The root of each hair is contained in a tubular pit of the epidermis called the hair follicle. The hair grows from the bottom of the follicle. It is nourished by the blood vessels in a papilla that extends into the follicle and, for a short distance, into the root of the hair. A minute muscle, the arrector pili, is attached to each hair follicle; under the control of the autonomic nervous system the muscle contracts to make the hair 閳ユ笩tand on end.閳?Most mammals possess tactile hairs, usually growing from the upper lip and eyebrows, with their roots set in erectile tissue richly supplied with sensory nerves.



In humans the development of the hair begins in the embryo, and by the sixth month the fetus is covered by a growth of fine hair, the lanugo. In the first few months of infancy the lanugo is shed and is replaced by hair, relatively coarse over the cranium and the eyebrows, but fine and downy over the rest of the body. At puberty coarse hair develops in the armpits and over the pubic region in both sexes; in males facial hair begins to grow coarse to form the beard. The rate of growth of the hair varies with the age of the person and with the length of the hair. When a hair is short, its rate of growth averages about 2 cm (about 鑱?in) per month; by the time the hair is a foot long, the rate of growth is reduced by one-half. The fastest growth is found in women from 16 to 24 years of age.



The form of the hair is one of the most important and reliable hereditary characteristics. The nearly black hair of the African, Papuan, and Melanesian grows from a curved follicle, which imparts a spiral twist, and is flat or tapelike in cross section. The hair of the Chinese, Japanese, and Native American is straight, coarse, and almost always black; it grows from a straight follicle, is round in cross section, and has an easily distinguished medulla. The hair of the European, Semite, and Ainu is wavy and intermediate between the straight and curly types; growing from a straight follicle, it nevertheless has a slight tendency to curl, is oval in cross section, and exhibits a range of color from light blond to black.



Disorders of the hair shaft or hair follicle cause abnormal growth or abnormal or premature falling of the hair. Certain abnormal conditions such as dull or dry hair are caused by physical or chemical agents. Too frequent use, for instance, of permanent-waving chemicals or of shampoos or lotions, especially those containing alcohol or free alkalies, often causes such conditions. The cause of excessive hairiness is obscure, but in several cases it has been traced to tumor of the adrenal cortex or to disorders of the pituitary gland, the thyroid gland, or the ovary. Premature graying of the hair is associated with anxiety, shock, deficiency diseases, and, in certain cases, hereditary elements.



Alopecia, or baldness, is also due principally to hereditary elements. Certain forms of baldness may, however, be due to other causes: alopecia prematura, in which the hair of a young person falls out without preliminary graying, may also be caused by seborrhea; while alopecia areata, in which the hair falls out in irregular patches, is believed by doctors to be caused by inflammation, nerve disorders, or local infections. Diffuse falling of the hair, ordinarily a normal phenomenon, may reach abnormal proportions after a fever higher than 39.4鎺?C (103鎺?F), during a debilitating disease, or as a result of invasive surgical procedures. No nonprescription hair 閳ユ笧estorers閳?actually prevent hair loss or grow hair. A drug called minoxidil, however, has shown some effectiveness in treating men and women with hereditary baldness.



Infections of the hair follicle also cause a variety of hair diseases. Tinea favosa, or favus, is caused by the fungus Achorion schoenleinii; it is characterized by the formation around the mouths of the follicles of small crusts, which frequently resemble a honeycomb. Tinea trichophytina, or ringworm, is caused by fungi of the genus Trichophyton. These diseases have been treated successfully by epilation (removal of the hair from the affected follicles), cleansing with soaps or oils to remove encrustation, and application of fungicides.



Hairy parts, particularly of the head and pubis, are subject to troublesome infestations by minute insects and mites, such as chiggers and lice.



Is this enough or want more????????



Count Dracula



What is human hair made of?

calsium and blood,same as ur nails ,



What is human hair made of?

Keratin, excess protein/amino acids that helps produce and nourish your hair and nails.



What is human hair made of?

keroatine



What is human hair made of?

Protein - called Keratin



What is human hair made of?

Natural plastic maybe, hee hee



What is human hair made of?

some say its keratin and some say its carbon



What is human hair made of?

human hair is made up of keratin



What is human hair made of?

Hair contains karatin %26amp; blood, but believe it or not it is mostly water %26amp; protien as strange as it may seem.



Stylist of 9 yrs.



What is human hair made of?

protein and so are the finger and toe nails



What is human hair made of?

Human hairs rather for that matter hairs of all living organisms are made up of Protiens.



What is human hair made of?

keratin



What is human hair made of?

Humans are hairy.



If you think that humans are pretty hairless creatures, you're wrong. All, we mean ALL, over your body, except for your lips, palms of your hands and soles of your feet are hairs, big and small. By the time you're an adult, you're likely to have about 5 million hairs growing out of your skin -- about the same number as a gorilla! The only difference is that most of a gorilla's hair is thick and long, and most of a human's is so thin and small it is extremely hard to see. You've got to look closely!



What is hair?



Hair is made of the same stuff that's found in horse hooves, bird feathers, antlers, horns, and your cat's or dog's claws and your fingernails! It's a body protein called keratin and it grows out of a minuscule opening of the skin called a follicle.



Why is some hair curly, some hair straight?



It all depends on the shape of the follicle out of which the hair is growing. Straight hair lies flat because it's round and grows out of round follicles. Curly hair bends because its cross-section is an oval. It comes out of oval follicles.



What makes some hair dark, some light, and some entirely white?



The same chemical pigment that determines skin color -- melanin. Not having melanin in your body gives you white hair; a little makes you strawberry blond; more makes you a red-head; even more brown-haired; and even more, hair that looks blue-black. Pretty remarkable, huh?



What do goosebumps have to do with hair?



Everything! When you are chilled, or startled, you sometimes develop goosebumps. What are they? Temporary bumps on your skin caused by muscles attached to hair follicles pulling those hairs upright! Goosebumps actually serve a purpose in animals. Fluffing up fur or feathers helps trap air and make them warmer or make them look bigger and scarier. What do goosebumps do for humans? You tell us.



What does puberty have to do with hair?



As you approach puberty, you are likely to discover that several things about your body -- including patterns of body and facial hair -- are going to change. You'll start developing hairy underarms, and pubic hair.... If you're a boy, you may find yourself wanting to shave the hair on your upper lip and on your chin; if you're a girl, you may have hairy legs for the first time in your life. Puberty makes life interesting, eh?



What is human hair made of?

Hair Protiens

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