Keratinocyte

Micrograph of keratinocytes, basal cells and melanocytes in the epidermis
Keratinocytes (stained green) in the skin of a mouse

Keratinocytes are the primary type of cell found in the epidermis, the outermost layer of the skin. In humans, they constitute 90% of epidermal skin cells.[1] Basal cells in the basal layer (stratum basale) of the skin are sometimes referred to as basal keratinocytes.[2] Keratinocytes form a barrier against environmental damage by heat, UV radiation, water loss, pathogenic bacteria, fungi, parasites, and viruses. A number of structural proteins, enzymes, lipids, and antimicrobial peptides contribute to maintain the important barrier function of the skin. Keratinocytes differentiate from epidermal stem cells in the lower part of the epidermis and migrate towards the surface, finally becoming corneocytes and eventually being shed,[3][4][5][6] which happens every 40 to 56 days in humans.[7]

  1. ^ McGrath JA; Eady RAJ; Pope FM. (2004). "Anatomy and Organization of Human Skin". In Burns T; Breathnach S; Cox N; Griffiths C. (eds.). Rook's Textbook of Dermatology (7th ed.). Blackwell Publishing. p. 4190. doi:10.1002/9780470750520.ch3. ISBN 978-0-632-06429-8. Archived from the original on 2020-05-20. Retrieved 2010-06-01.
  2. ^ James W, Berger T, Elston D (December 2005). Andrews' Diseases of the Skin: Clinical Dermatology (10th ed.). Saunders. pp. 5–6. ISBN 978-0-7216-2921-6. Archived from the original on 2010-10-11. Retrieved 2010-06-01.
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