Epidermis

The epidermis is the outermost layer of the skin. It serves as a protective barrier between the body and the external environment. Here are some key points about the epidermis:

• Structure: The epidermis is primarily made up of keratinocytes, which produce keratin, a tough, protective protein. It lacks blood vessels and receives nutrients through diffusion from the underlying dermis.
• Layers: The epidermis has multiple sub-layers (from deepest to most superficial):
  1. Stratum basale (basal layer): The deepest layer, where new keratinocytes are produced through cell division.
  2. Stratum spinosum (prickle cell layer): Provides strength and flexibility.
  3. Stratum granulosum (granular layer): Where keratinocytes begin to die and keratin production increases.
  4. Stratum lucidum: Found only in thick skin (like the palms and soles).
  5. Stratum corneum (horny layer): The outermost layer, composed of dead keratinized cells that are continuously shed and replaced.
• Functions:
  • Protects against environmental damage (UV radiation, pathogens, chemicals).
  • Prevents water loss (via a waterproof barrier).
  • Contains melanocytes that produce melanin, which gives skin its color and protects against UV radiation.
  • Houses Langerhans cells that play a role in immune response.

If you want information on a specific aspect of the epidermis, such as its pathology, cellular composition, or role in certain diseases, feel free to ask!