What causes the male body to get hairier the same time the head gets balder?

It is my understanding that male pattern baldness is caused by (or at least associated with) endocrine hormones (androgens), especially testosterone.

Why does only the hair on the head lessen from this, and not the hair on the rest of the body?

As I get older, I see my hairline receding, and the rest of me getting hairier. If this keeps up, by the time I die I’m gonna look Yul Brenner and Chewbacca had a baby.

As for me I don’t have a receding hair line but I do have a bit more body hair than when I was 20. (I’m 35) Pehaps the issues are unrelated.

genes, Rev, genes.

Well, it seems a scientist in England thinks that, because he grew hair, from a part of one of his own head-hair follicles, on his wife’s arm – we can soon grow head hair, by such a trivial transplant procedure from ourselves or other persons, possibly first cloning the follicle parts in vitro before implanting them.
http://www.sfgate.com/cgi-bin/article.cgi?file=/news/archive/1999/11/03/national1318EST0710.DTL

Ray (The right to hair arms? The hair to right arms? Hair tomorrow, gone to Durham?)

The same thing which makes northerners head for Florida when they retire.


Mark
“Think of it as Evolution in action.”

According to Unca Cece, at least with respect to ears and noses: This problem, which is common among men as they age, is a manifestation of the law of conservation of hair.

His full report is contained in: http://www.straightdope.com/classics/a4_124.html

I imagine it’s the same thing that causes women to start growing facial hair. Those male hormones, ya gotta love 'em.

We know its genes & thus hormones [which are gene regulated], but several hundred messages here can’t tell us WHY we have hair where we do. Of course, this is the same ask asking why we have two arms.

Men have hair on their ears & in their noses & women do not. What a great sexing tool in this day of gender confusion.

Another factor to consider is the fact that the hair on the head grows continuously while body hairs grow in cycles-the hair grows, stops growing and then later falls out, replaced by a new hair. Imagine having to trim your armpit every couple of months.

Gravity. Everything settles south eventually.

your humble TubaDiva
who expects all the good stuff to be around her knees any day now

One theory: lower blood circulation to the scalp and increased blood circulation elsewhere may cause the hair migration.

One baldness cure calls for using 1 tsp of cayenne pepper in your daily shampoo. This increases the blood supply to the scalp.

I’m tempted to try this, as my temples are getting higher, but I don’t want to shell out the bucks for Rogaine.

OK.

Why we have hair where we do. Insulation and, believe it or not, lubrication.

Nose hair: filters out large particles.
Ear hair: Keeps dirt and hopefully bugs out of the ears.
Under arm hair: Natural lubrication.
Groin hair: Same as under arm hair.
Ass hair: Same as groin hair.

Bodily hair: Remains of a natural temperature controlling fur coat. Even today, body hair responds to heat and cold by raising or compacting according to the temperature.

Head hair: Provides protection and insulation for the brain. Ever notice how slippery it can be? A poorly aimed blow would hit the hair and actually slide off doing less damage than if the skull was bald.

Beards: Facial insulation and protection. (Acts similar to head hair.) NOTE: The beard hair is different in texture and toughness from other bodily hair.

Later, head hair became a great beauty feature.

The diminishment of male head hair is possibly connected with aging when the older male, having survived beyond the violent teen and younger years, slows down and potentially no longer requires the body to expend energy and resources into protecting the skull. Genetics has a lot to do with it here and we could go into mutations caused by our mildly variable and radioactive sun, along with natural selection, but I will not.

Testosterone, of course, has a lot to play in the matter. The male needed more hair as the hunter gatherer and fighter while the woman needed less because her body has that layer of fat under the skin to provide her and any unborn child with insulation.


Mark
“Think of it as Evolution in action.”

I asked the post-doc in my lab about this in passing. His response: The follicular cells in the head have more testosterone receptors than the cells that produce body hair–therefore the two “types” of hair cells exhibit different responses to testosterone.

Genetics are obviously invovled and the answer is more complicated than what’s above. I remember a more complete explanation from my undergrad genetics but don’t have it in front of me. Somebody could probably add to this.

647, that would assume then that a topical or internal application of testerone would grow hair. But it does not.

I think that bald is just an optical illusion because if you look closely, there are fine hairs there, called ‘down.’ As a matter of fact, look at your face and its got a lot of down on it but you have to look closely.

But what about those weird, fibrous hairs that grow on the outer edge of ears?

Actually handy, I think 647’s response would indicate that a topical or internal application of testosterone would cause hair LOSS. I think it’s the testosterone that causes head baldness.

Most of the priests, ministers & monks I have met are bald. You might have something there Rev.