Medical research

Solving a biological puzzle: How stress causes gray hair

When Marie Antoinette was captured during the French Revolution, her hair reportedly turned white overnight. In more recent history, John McCain experienced severe injuries as a prisoner of war during the Vietnam War—and ...

Psychology & Psychiatry

What puts women off bearded men?

Women who find bearded men less attractive may be deterred due to their potential risk for carrying ticks, bugs and lice, according to a University of Queensland study published today.

Psychology & Psychiatry

Compassion training for parents may reduce their children's stress

A new study from researchers at the University of Wisconsin–Madison shows that the young children of parents who take part in a compassion-based training program develop lower levels of the stress hormone cortisol over ...

Psychology & Psychiatry

New year, new you? Why we think a better body will be a better self

Is a better body a better self? Is a perfect body our best self? In the visual culture we inhabit we increasingly believe that a better body will lead to a better life, one where we are happier, have a better job, a better ...

Medical research

Hair growth finding could make baldness 'optional'

The best way to avoid baldness is to stop hair from falling out in the first place. Now, researchers say a new hair growth discovery might help men keep their locks for a lifetime.

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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