If you shave hair off your body, how does your body know to grow it back?

Question

The hair on your body usually stops groing when it reaches a certain length. But when you shorten it, it grows back. How can your body tell how long your hair is, seeing as your hair has no nerves?

Answer 1

when you shave the hair, the follicle is stimulated, and this incourages it to grow back faster, and possibly thicker. for some women, the day after they shave their legs, the hairs have already become hard, short prickles.

ever see that episode of seinfield where they talk about saving chest hair? they said there that the more you shave, the faster and more thicker the hair comes back. i think there is some truth in that.

Answer 2

Each hair folicle is "programmed" to be active and domant for certain periods. The active and dormant cycles are controled by hormones in different parts of your body.

Your hair doesn't know to grow when it has been shaved. In fact sometimes in the emergency room they have to shave a person's eyebrows... and it might not grow back for a year. Other people it comes back in a month.

You body just automatically keeps making hair (unless you are starving) and your folicle basically stops it from growing after a certain amount of time.

Make sense?

Answer 3

It's not that it stops growing at a certain length, it's that it usually falls out before it gets super long. Your hair generally grows at the same, constant rate.
In short, your body can't tell how long your hair is.

Answer 4

The hair on your body grows continuously at about the same rate.

Answer 5

Hair on your body is designed to:
1) Keep you warm (Legs/Arms/Head)
2) Keep out dust/dirt (Peach fuzz in ears/nose)