OT Hair, why does it grow the way it does.

I reckon it is the sun shining on hair root makes it grow.
Then again it could be the lack of sun that makes it grow.
Maybe it is something that just happens.

I think I will go back to fishing before some one picks holes in my "research"!!!

Jim,

The following is straight out of my clinical methods text book so please excuse some of the mumbo jumbo, but it does give a bit of an explanation

"Humans have three different types of hair:

• Lanugo, the fine hair that covers nearly the entire body of embryos

• Vellus hair, the short, fine, "peach fuzz" body hair that grows in most places on the human body in both sexes

• Terminal hair, the fully developed hair, which is generally longer, coarser, thicker, and darker than vellus hair

The most noticeable part of human hair is the hair on the head, which can grow longer than on most mammals. The other parts of the human body feature different types of hair. From childhood on vellus hair covers the entire human body regardless of sex or race. The density of the hairs (in hair follicles per square centimeter) varies from one person to another.

The rising level of male hormones (androgens) during puberty causes a transformation process of vellus hair into terminal hair on several parts of the male body. The hair follicles respond to androgens, primarily testosterone and its derivatives; the hair in these locations can be termed androgenic hair. The rate of hair growth and the weight of the hairs increase. However, different areas respond with different sensitivities. As testosterone level increases, the sequence of appearance of androgenic hair reflects the gradations of androgen sensitivity. The pubic area is most sensitive, and heavier hair usually grows there first in response to androgens.

Areas on the human body that develop terminal hair growth due to rising androgens in both sexes, men and women, are the underarms and the pubic area. In contrast, normally only men grow androgenic hair in other areas.

Individual hairs alternate periods of growth and dormancy. During the growth portion of the cycle, hair follicles are long and bulbous, and the hair advances outward at about a third of a millimeter per day. After three to six months, body hair growth stops (the pubic and armpit areas having the longest growth period). The follicle shrinks and the root of the hair grows rigid. Following a period of dormancy, another growth cycle starts, and eventually a new hair pushes the old one out of the follicle from beneath. Head hair, by comparison, grows for a long duration and to a great length before being shed. The rate of growth is approximately 1.25 centimeters, or about 0.5 inches, per month."

Have a good one.

this post is useless without pictures :)