If body hair is programmed to grow to a specific length and stop growing, then how does the hair grow when you

Question

cut it? can you explain it in a scientific way please?

btw...I am talking about the hair we have in legs and arms.

Answer 1

It's a common misconception that hair will continue to grow until it has reached a set length and then will stop.

What actually is happening is that each individual hair follicle is going through a cycle, whereby it is created, produces a hair, stops growth, and then dies. All hair is managed this way, irrespective of the position on the body.

Usually the rate of hair follicle death is approximately the same as the rate of new follicle development thus keeping the actual number of hairs in an area constant. In bald or balding people the rate of replenishment is clearly exceeded by the rate of follicle death.

Essentially what is setting the length of the hair is the time that the hair follicle is allowed to remain in this cycle without dying. Head hairs may take several years to complete the cycle and as such grow long, whereas eyebrow hairs may speed through it in a matter of months and are much shorter as a result.

The length of the cycle in different areas of the body is set by hormone levels

Answer 2

your hair grows to a certain length then stops growing and the sheath arround the folicle tightens to keep the hair in place. it is in stasis for a period of time then it falls out and a new one grows in its place. in the case of your arms. if you shave a spot then monitor the growth you will see that some off the hair grows a little then stops, and some takes longer to start growing. the hairs grown stop and fall out at different times, so it is hard to see the process. if they did it all at once we would be bald certain times of year.

Answer 3

It all grows at the same speed, more or less; body hair simply falls out a lot more often than hair on our heads.