Human epidermis

Epidermis: superficial layer of human skin

What is (meaning)
The epidermis is the superficial part of the human skin. It is formed by epithelial tissue being thinner than the other part of the skin (dermis). The meaning of the word epidermis comes from the Greek, where "epi" means above and "dermis" means skin.
Main functions of the epidermis:
- Body protection. The large presence of keratin enables this function.
- Absorption of ultraviolet (UV) rays from the sun. This function is performed by melanocytes present in the epidermis.
- Fight against microbes that penetrate the human skin. This function is performed by the Langerhans cells present in the epidermis.
- Enables touch sensation through Merkel cells.

Main features of the human epidermis:

- It is formed by epithelial tissue. This tissue is scaly, keratinized and stratified.
- The epidermis is made up of four cell types: keratinocytes (about 90% responsible for keratin production), melanocytes (about 7.5% responsible for melanin production), Merkel cells and Langerhans cells.
- The epidermis, in much of the human body, is composed of four layers: basal layer, spiny layer, granular layer and thin corneal layer (thin skin). In areas of the body where the contact (friction) is greatest, there is a fifth layer called the thick corneal layer (thick skin).
Did you know?
The branch of medicine that studies and treats the human epidermis is called dermatology.

Last reviewed: 12/17/2018

By Elaine Barbosa de Souza
Undergraduate student in Biological Sciences, Methodist University of São Paulo.