How does the human body determine hair length?

Question

As I was taught in High School, hair is there to keep the body warm.
Now I've noticed that if I shaved my armpits the hair will grow back to the same length as before, but will not grow any further (I've never seen people with armpit hair reaching their ankles).

Yet hair on our heads grow a lot longer than that. So how does the body know when to stop the hair growth?

Also if hair grows to a certain length and stops, and if it is made to warm body parts, how come the hair on heads can get so long? Surely if the hair grows past shoulder length it won't protect the head even if it gets longer...

Answer 1

First, what is hair. hair is known as pilus (single) Pili (plural) Hair is a slender filament of keratinized cells that grow from an oblique tube called a hair follicle. Hair is found all over the body we grow three kinds Lanugo a fine downy hair found on babies Next we have vellus hair witch is unpigmented. finally we have terminal hair witch is coarser longer and is pigmented (that is the hair your thinking of) the terminal hairs on our arms do not keep us warm in any way. They are not close enough together to provide any protection from the cold. they are also the wrong type of hairs to keep us warm. The hair growing past your shoulder dose not serve a purpose but it is not a detriment so it stays. the hair under your armpit is removed by mechanical force when a person moves.

Answer 2

Hair on most parts of the body is subject to abrasion and other damage such as bleaching by the sun. I never shave the hair on my arms, but it stays about the same length because as it grows and dries out, the ends break off. Under some conditions the hair gets dryer and more brittle and thus shorter.
People with long hair normally have to take considerable care of it.

Answer 3

Good question! I saw a program on transplanting head hair to the eyelashes and the implanted hair would keep growing as if it is on the head, needing regular trimming. Somehow the DNA in the root determined the length of the hair no matter where it is on the body. Now I wonder how long would you grow your eyelashes if they would grow...ehehe.
Fun question to ponder though. Thx.

Answer 4

Pantene products coat the hair shaft with polymers (the professional-V) to delicate chop up ends and injury. it provides you with 'the look of fit hair', despite the fact that it incredibly will never be any fit. That works for awhile. With persevered use the polymers ought to boost on the hair shaft till it breaks off. Pantene should not be your unique product. substitute using it with yet another product to circumvent the boost. It honestly won't make your hair improve any quicker. reliable food, much less warmth throughout the time of styling, soft brushing and brushing, and scalp rubdown might produce extra effectual outcomes. Scalp rubdown will motivate thicker hair too. Use your finger tips or knuckles whilst massaging. do no longer use your finger nails.

Answer 5

wow you got me there bit of a hair raiser that one anyway who gives a toss , and if it is for keeping the body warm how come mine has almost gone,