“But the very hairs of your head are all numbered. Fear ye not therefore, ye are of more value than many sparrows.”
They are the only cells in the human body that repeatedly die and self-regenerate throughout life. They are probably the only cells in the body that inspired a Broadway play named after them. And science considers them so interesting that several branches of science are studying them. I am talking about hair cells.
As scientists are learning more about hair, they are coming to greater appreciation of, as one researcher put it, hair’s bewildering biology. A Harvard molecular biologist admitted that one of the reasons we know so little about hair is that scientists have avoided studying this complex structure.
The average scalp has about 100,000 hairs growing at any one time. Each hair follicle produces hair for about two to five years, followed by a rest period of four to six months. A miniature assembly line of cells divides within the follicle, pushing older hair cells upward through the skin. Pigmentation is added as each new cell is produced. When the follicle is at rest, it shrivels and many of its cells die. However, seed cells, promising new life to the follicle, hide within it waiting for the signal to spring back to life. As humans grow older, the resting time of the follicles increases and growing time decreases, especially in men. So if you find yourself balding, you’re not necessarily losing your hair. It’s just that your hair is spending more time resting than it used to.
God tells us that He cares so much about each one of us that He even knows how many hairs we have on our head!
Dear Father in heaven, I do not understand how You can keep track of so many details about so many people. Nor do I understand how You can love us so. But I trust in Your promises to me in Jesus Christ. Amen.
Weiss, R. 1991. “Fuzzy science.” Science News, v. 139, Mar. 16. p. 169. Photo: Strand of human hair at 200x magnification.