DERM-L5

Skin Structure and Function

• Keratinocytes in the epidermis produce the protective fibrous protein called keratin.
• The basement membrane zone in the skin acts as a barrier between the epidermis and dermis, anchoring the epidermis to the dermis.
• The primary function of the skin is to protect the body from external factors, regulate body temperature, and maintain hydration.
• Melanocytes in the skin produce melanin, which provides skin pigmentation and protects against UV radiation.

Skin Layers

• The stratum basale (basal layer) is responsible for regulating body temperature.
• The dermis contains nerves and blood vessels.
• The dermis is also responsible for scarring and tattooing.
• The hypodermis is also known as subcutaneous fat.
• The dermis contains sweat glands and hair follicles.

Skin Lesions

• A macule is a flat, non-palpable lesion measuring 1cm.
• A papule is a raised lesion larger than 0.5 cm.
• A plaque is a plateau-like lesion larger than 0.5 cm.
• A vesicle is an elevated lesion containing fluid measuring 0.5 cm.

Skin Changes

• Lichenification is a thickened skin with distinct borders.
• An excoriation is a shallow hemorrhagic excavation caused by scratching.

Other

• Langerhans cells in the epidermis function as immune cells, recognizing and processing antigens.
• The dermo-epidermal junction is the layer of basal cells joining the epidermis to the dermis.
• The Fitzpatrick Scale is used to classify skin types based on their response to UV radiation.
• Genomic analysis shows that the African American genome is composed of varying degrees of African, European, and Indigenous American ancestry.