I recently shaved my head and discovered an area where no hair grows. When I was in elementary school a fellow student and I raced to the same urinal and I slammed my head right into the wall. I received two stitches in this area.
I would guess scar tissue.
What is it about scar tissue that prevents hair?
Destroyed hair follicles.
I take it that follicles don’t grow back or reproduce when skin heals? Does science know why?
Skin is a more complicated organ than most people realize. It will no more regrow “good as new” than an amputated finger or limb. Rather than having a highly organized matrix of specialized tissues, what fills the gap is a jumble of cells.
Why would you think they would? If the follicles were destroyed, why (or how) would new ones appear?
Mitosis or meiosis? I don’t know, i’m stupid this way. I don’t apply biology and anatomy in harmony. I’d be the worst doctor ever. Just asking
I learned in Physiology class that scar tissue has no sebaceous (oil) glands or sweat glands, either. This can be a real issue with large areas of scar tissue such as from a large burn. It also doesn’t stretch properly. You’re right, skin is very complicated.
The scar tissue probably didn’t "destroy the hair follicles. A few were ripped away with the skin during the accident. The tissue knit together (aided by the stiches), but the edges of the cut includes a thin strip of pure scar tissue, which can’t “regrow” the hair and whatnot.
Brevity rules the thread.
When my youngest son was a toddler, he had skull surgery. They made an incision going over the top of his head from one ear to the other. They did a zig-zag cut, because hair will never grow on top of the scar, and it’s easier to hide that with a zig-zag cut rather that a straight one. Not that he really cares- he likes his hair cut really short and the scar is rather visible. He thinks its cool.
I can definitely see how that might be cool looking to a young person. Are these a bunch of small zig-zags or a handful of fairly large ones? Or do you have a picture?
That’s because there’s no organization or alignment to the collagen in scar tissue. It’s really just a chunk of tissue put there to plug the hole.
I remember reading something a while back about the treatment of burn victims that involves laying down a sterile gel template in the hopes that it could give the regrown skin tissue more structure.