Hair and nail structure and function

Alfredo Rossi, Luca Barbieri, Giuseppe Pistola, Paola Bonaccorsi, Stefano Calvieri

Research output: Contribution to journalArticlepeer-review


The hair and nail are skin appendages that share with the skin a common origin from the ectodermal layer. They fulfil important protective and cosmetic physiologic function. After intrauterine life, hairs are divided, by size in two major types: vellus and terminal. Terminal hair is described as being substantial or large in size with a diameter of about 60mm. The scalp hair is a typical terminal hair. Vellus hairs are smaller, more lightly pigmented and the diameter is less than 30mm. The hair has a growth cycle consisting in different phases: anagen, telogen, catagen. The nail provides protection to the distal digit as well as aesthetic adornment and dexterity. Hair and nail disorders have a deep impact in the patient self-confidence and relation life. A vast spectrum of nail or hair alterations can be observed during the course of systemic disease although a causative association is seldom proved. A deep knowledge of the structure and physiology of the nail is necessary to correctly approach the pathogenesis of nail disorders.

Original languageEnglish
Pages (from-to)1-8
Number of pages8
JournalJournal of Applied Cosmetology
Issue number1
Publication statusPublished - Jan 2003


  • Hair
  • Nail
  • UV Protection

ASJC Scopus subject areas

  • Dermatology


Dive into the research topics of 'Hair and nail structure and function'. Together they form a unique fingerprint.

Cite this