Epidermis

Definition

The epidermis is the outermost layer of the skin, providing a protective barrier against environmental damage. It consists of multiple sublayers, including the stratum corneum and the basal layer.

5 Must Know Facts For Your Next Test

1. The epidermis contains melanocytes, which produce melanin to protect against UV radiation.
2. It does not contain blood vessels and receives nutrients through diffusion from the underlying dermis.
3. Keratinocytes are the most abundant cells in the epidermis, playing a key role in forming a protective barrier.
4. Epidermal turnover, or the process by which old cells are shed and new cells are produced, typically takes about 28 days.
5. The stratum corneum is the outermost sublayer of the epidermis and is composed primarily of dead keratinized cells.

Review Questions

• What type of cells are most abundant in the epidermis?
• How does the epidermis receive its nutrients if it lacks blood vessels?
• What is the function of melanocytes found in the epidermis?

Related terms

Dermis: The layer beneath the epidermis that contains blood vessels, nerves, and connective tissues.

Melanocyte: A cell in the basal layer of the epidermis responsible for producing melanin pigment.

Stratum Corneum: The outermost sublayer of the epidermis consisting mainly of dead keratinized cells.