Quote from: zirconia on November 06, 2017, 06:13:53 AM
Hi, Cindy
This sounds intriguing. Assuming an average monthly growth rate of around 12 mm, and given that some men can grow quite long beards I assume that the six week cycle you mention probably doesn't refer to the anagen-catagen-telogen cycle.
Do you mind elaborating a bit, if it's not too much trouble?
I am afraid that this is stretching my old brain to work on thoughts from some 45 years ago.
We were interested in hair growth cycles as in pattern of hair growth, at the time I think anagen was recognised and a dormancy that we would now call telogen (I think but I am not up on the terminology). What we were interested in was how cycles of growth occurred.
Now what we worked on (royal we) was that although the majority of hair was growing at a particular time, a fact that we could demonstrate by plucking hairs from different parts of the animals body and measuring the length on a daily basis. Not all parts of the body grew hair at the same time. Hair growth occurs in set patterns or waves.
Hence if you take your rat and carefully shampoo and shave it to a bald skin and then start to measure hair growth on a daily basis, again by plucking random hairs at set body areas, the hair growth is not uniform but occurs in a 'wave'. This was from memory quite set in the pattern.
How does this fit in our modern 'hipster'? Well a persons beard will not grow uniformly but you will not detect the difference unless you measure hair growth along the beard on a set time basis. However if you clean shave a face and watch how hair grows you will find a wave effect as some follicles become active and start to grow, followed in time by another set of follicles. As far as laser goes you will hit the activated growing follicle but of course have no effect on the resting. Waiting for the wave to catch up is required to hit the next series of follicles to become active.This wave in humans is around the 5-6 week mark on the face.
I think in humans the wave on the face is from the sideburns towards the cheeks, the snout is independent.
I remember the wave bit but the rest is lost in time I sort of remember that we were interested in one of the steroid hormones being involved but I can't remember which. Shortly after I moved into the equally fascinating area of cortisol secretion in eels as they adapt to salt water from fresh. Eventually I some how ended up in cancer research and diagnostics.
If I recall and how could I forget, my role in this study was that of a hair measurer. So I would collect hairs by plucking rats on a set pattern, sticking the hairs onto sticky tape and measuring their length.