Related topics: stem cells

Carnivorous plants: No escape for mosquitoes

Physically bound to a specific location, plants have to devise special ways to secure their supply of vital nutrients. Most plants have developed a root system to the nutrients they need in order to survive out of the soil. ...

A polar-bear-inspired material for heat insulation

For polar bears, the insulation provided by their fat, skin, and fur is a matter of survival in the frigid Arctic. For engineers, polar bear hair is a dream template for synthetic materials that might lock in heat just as ...

What's your attitude about body hair removal?

As beachgoers scramble to trim their nether regions ahead of swim season, new UNLV research shows they aren't alone in their ambitions for a bare bikini line.

Experts develop nanolasers on silicon

Researchers at Cardiff University have shown tiny light-emitting nanolasers less than a tenth of the size of the width of a human hair can be integrated into silicon chip design.

All ears: Genetic bases of mammalian inner ear evolution

Mammals have adapted to live in the darkest of caves and the deepest oceans, and from the highest mountains to the plains. Along the way, mammals have also adapted a remarkable capacity in their sense of hearing, from the ...

Experts comb through DNA from possible Da Vinci hair

A lock of what some historians think is Leonardo da Vinci's hair went on display Thursday at a museum in his Tuscan birthplace as they seek to prove it contains his DNA 500 years after the genius died.

page 1 from 23

Hair

Hair 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.

This text uses material from Wikipedia, licensed under CC BY-SA