Hair
hideHair is a protein filament that grows through the epidermis from follicles deep within the dermis. The fine, soft hair found on many nonhuman mammals is typically called fur; wool is the characteristically curly hair found on sheep and goats. Found exclusively in mammals, hair is one of the defining characteristics of the mammalian class. Although other non-mammals, especially insects, show filamentous outgrowths, these are not considered "hair" in the scientific sense. So-called "hairs" (trichomes) are also found on plants. The projections on arthropods such as insects and spiders are actually insect bristles, composed of a polysaccharide called chitin. There are varieties of cats, dogs, and mice bred to have little or no visible fur. In some species, hair is absent at certain stages of life. The main component of hair fiber is keratin.
The hair can be divided into three parts length-wise, (1) the bulb, a swelling at the base which originates from the dermis, (2) the root, which is the hair lying beneath the skin surface, and (3) the shaft, which is the hair above the skin surface. In cross-section, there are also three parts, (1) the medulla, an area in the core which contains loose cells and airspaces (2) the cortex, which contains densely packed keratin and (3) the cuticle, which is a single layer of cells arranged like roof shingles.
For more information about Hair, read the full article at
Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
News tagged with hair
Studying hair of ancient Peruvians answers questions about stress
Other Sciences / Archaeology & Fossils
Dec 09, 2009 |
4 / 5 (3) |
0
(PhysOrg.com) -- Recent studies show that one in three Canadians suffer from stress and the number is on the rise. But stress isn't a new problem.
Ancestry attracts, but love is blind
Nov 20, 2009 |
4 / 5 (1) |
1
People preferentially marry those with similar ancestry, but their decisions are not necessarily based on hair, eye or skin colour. Research, published in BioMed Central's open access journal Genome Biology, shows that M ...
Single gene may cause curly hair
Nov 10, 2009 |
4.4 / 5 (8) |
0
(PhysOrg.com) -- Scientists in Australia have identified a single gene that strongly influences whether you have curly or straight hair.
Now hear this: Mouse study sheds light on hearing loss in older adults
Nov 09, 2009 |
5 / 5 (1) |
0
(PhysOrg.com) -- Becoming "hard of hearing" is a standard but unfortunate part of aging: A syndrome called age-related hearing loss affects about 40 percent of people over 65 in the United States, and will afflict an estimated ...
Color differences within and between species have common genetic origin
Oct 22, 2009 |
not rated yet |
0
(PhysOrg.com) -- Spend a little time people-watching at the beach and you're bound to notice differences in the amount, thickness and color of people's body hair. Then head to the zoo and compare people to chimps, our closest ...
Now hear this: Scientists show how tiny cells deliver big sound
Oct 22, 2009 |
3.7 / 5 (3) |
0
Deep in the ear, 95 percent of the cells that shuttle sound to the brain are big, boisterous neurons that, to date, have explained most of what scientists know about how hearing works. Whether a rare, whisper-small second ...
Fish Sense Other Fish Via Ripples
Oct 15, 2009 |
5 / 5 (2) |
0
Although humans experience their world through vision, touch and the other senses, many creatures gather information about their surroundings through unique sensory mechanisms that humans don’t have.
Study: Hairstylists can help identify older clients who need health services
Sep 08, 2009 |
4.5 / 5 (2) |
1
Hairstylists may have a unique opportunity to help steer their elderly clients to needed health services, according to a small, exploratory study.
Scientists identify genetic cause for type of deafness
Sep 03, 2009 |
not rated yet |
0
A team led by scientists from The Scripps Research Institute has discovered a genetic cause of progressive hearing loss. The findings will help scientists better understand the nature of age-related decline in hearing and ...
Don't brush with baldness: put down that comb
Aug 10, 2009 |
5 / 5 (1) |
0
Put that comb back in your handbag -- a study by an Israeli dermatologist has found that too much combing of the coiffure leads to hair loss, the daily Haaretz reported on Monday.
From nerve roots to plant roots -- research on hereditary spastic paraplegia yields surprises
Aug 06, 2009 |
not rated yet |
0
Sprouting. Branching. Pruning. Neuroscientists have borrowed heavily from botanists to describe the way that neurons grow, but analogies between the growth of neurons and plants may be more than superficial. A new study from ...
Stress can induce hair loss, and is especially notable in women
Jul 24, 2009 |
not rated yet |
0
The New York Times recently reported that Alaska Gov. Sarah Palin's hair was thinning as a result of extreme stress. If so, doctors say, she's not the only one.
Understanding hair biology could pave way for treating disorder
Jul 23, 2009 |
not rated yet |
0
A change in the way we process lipids could mean relief for those who suffer from cicatricial alopecia, or scarring hair loss.
Safer hair dyes and cosmetics to be made from Shetland seaweed
Jul 23, 2009 |
not rated yet |
0
Scientists have launched a project to make hair dye out of seaweed from around the Shetland Islands.
Analysis of Copernicus putative remains support identity
Jul 07, 2009 |
5 / 5 (4) |
0
Swedish and polish researchers now publish results from the analysis of the putative remains of Copernicus. A DNA-analysis of shed of hairs found in a book from Museum Gustavianum, Uppsala University, was ...
