Topic overview

Start with the big picture

The epidermis is an avascular, keratinized epithelium nourished by diffusion from the dermis. Its layers run from the stratum basale through the spinosum and granulosum to the corneum; the lucidum is present in thick skin of the palms and soles. The dermis is vascular connective tissue with papillary and reticular layers. It supports the epidermis and contains skin appendages, vessels, nerves, and sensory corpuscles. Dermal papillae interlock with epidermal ridges, reinforcing their interface. Beneath these layers, the hypodermis consists of loose connective tissue and adipocytes. It anchors and cushions the skin, provides insulation and energy storage, and houses major vessels and nerves. Together, these layers explain skin structure and provide a basis for understanding selected clinical correlations.