Dictionary > Keratinocyte

Keratinocyte

Definition
noun, plural: keratinocytes
The predominant type of cell in the epidermal layer of the skin
Supplement
The skin serves as an outer protective covering of many animals. In particular, the skin of mammals and humans is composed of two major layers: (1) epidermis and (2) dermis. The epidermis is the outer, waterproofed layer of the skin and the dermis is the layer below the epidermis. The epidermis is a stratified squamous epithelium made up mainly of (95%) keratinocytes. The other cells present in the epidermis are Merkel cells, melanocytes, and Langerhans cells.
A keratinocyte is a highly specialized epithelial cell. The (basal) keratinocytes in the deepest layer of the epidermis (i.e. stratum germinativum) divide mitotically to provide new cells for the upper layers of the epidermis. Newly-produced keratinocytes move up and differentiate into anucleated cells forming desmosomes between them. They secrete keratin and lipids that provide mechanical strength to the skin. Keratinocytes (now called corneocytes) on the outermost layer of the epidermis (i.e. stratum corneum) are regularly shed through desquamation.
The keratinocytes, therefore, play a major role in providing a protective barrier against infective agents, environmental damage, and water loss. They are also involved in the local immune response against antigens that gained entry to the skin. They release chemokines (e.g. CXCL10 and CCL2) that attract leukocytes to the site.
Word origin: keratin– + –o– + –cyte (“cell”)
Synonym(s):

  • skin cell

See also:

  • keratin
  • cornification
  • skin
  • corneocyte


  • You will also like...

    Wart-like leaf galls on grape leaves
    Plant Cell Defense

    Plants protect themselves by releasing hydrogen peroxide to fight against fungal invasion. Another way is by secreting c..

    Chromosomes X and Y and Sex Determination
    Chromosomes X and Y and Sex Determination

    This tutorial looks at sex determination via the sex chromosomes, X and Y. Read it to get more info on X and Y chromosom..

    An artist's depiction of the origin of amphibians
    Amphibians & Early Reptiles

    Obtaining air outside an aquatic environment required species to acquire suitable adaptations, and this was the case of ..

    Selective Breeding
    Selective Breeding

    Gregor Mendel's studies into Monohybrid and Dihybrid crossing and Charles Darwin's study of evolution and natural select..

    Human perception in action
    Human Perception – Neurology

    This tutorial investigates perception as two people can interpret the same thing differently. Know more about human perc..

    Adaptive Radiation
    Adaptive Radiation

    The diversification of several new species from a recent ancestral source, each adapted to utilize or occupy a vacant ad..

    Related Articles...

    No related articles found

    See all Related Topics