| Popis: |
Of all the adnexa of the skin, the hair has the most elaborately balanced structure. Only minor deviations from the norm are compatible with the formation of a viable hair. Two of the basic rules of hair morphogenesis are these: 1. One papilla forms only one hair at one time; 2. Each hair is a unit, a single thread made up of concentric layers, and does not branch or become subdivided. These rules hold true not only for human hair. From the finest hair of the chinchilla fur to the coarsest vibrissa of the tiger, hair formation follows the same rigid rules. |
