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...

    squirrel
    Animal Water Regulation

    Animals adapt to their environment in aspects of anatomy, physiology, and behavior. This tutorial will help you understa..

    Plant Water Regulation
    Plant Water Regulation

    Plants need to regulate water in order to stay upright and structurally stable. Find out the different evolutionary adap..

    Water Cycle
    The Water Cycle

    The water cycle (also referred to as the hydrological cycle) is a system of continuous transfer of water from the air, s..

    Adaptation Tutorial
    Adaptation Tutorial

    Adaptation, in biology and ecology, refers to the process or trait through which organisms or the populations in a habit..

    Plant biology
    Plant Biology

    Plantlife can be studied at a variety of levels, from the molecular, genetic and biochemical level through organelles, c..

    Early Earth
    The Origins of Life

    This tutorial digs into the past to investigate the origins of life. The section is split into geological periods in the..

    Related Articles...

    No related articles found

    See all Related Topics