Integumentary System Physiological Phenomena
The processes by which skin, hair, nails, and associated glands protect the body, regulate temperature, sense stimuli, and maintain tissue health.
Epidermal barrier: The outer skin’s layered structure limits water loss and blocks chemicals, microbes, and physical damage. Its lipids and tightly joined cells provide the integument’s first line of protection.
Epidermis: The outer epithelial layer of skin, renewed continuously by dividing cells in its basal layer. Its keratin-producing cells form the surface barrier.
Atopic dermatitis: A chronic inflammatory skin disease associated with itch, barrier dysfunction, and recurrent eczema. It shows how impaired barrier function and immune activity can reinforce each other.
Mucosal barrier: A protective lining of mucus-producing epithelium found in body passages exposed to the external environment. Unlike dry, keratinized skin, mucosa protects moist internal surfaces.
Thermoregulation: The processes that keep an organism’s body temperature within a viable range. Skin blood flow and sweat production adjust heat loss at the body surface.
Dermis: The connective-tissue layer beneath the epidermis, containing vessels, nerves, follicles, and glands. Its vascular and structural tissues support skin function and repair.
Acne vulgaris: A disorder of pilosebaceous units involving clogged follicles, inflammation, and characteristic lesions. It arises where sebum production, follicular keratinization, and microbes interact.
Innate immunity: The rapid, broadly targeted immune defenses present from birth. Skin immunity is one specialized part of this wider defense system.
Eccrine sweat gland: A widespread skin gland that releases watery sweat directly onto the skin surface. Its secretion cools the body as it evaporates.
Hypodermis: The layer of connective tissue and fat beneath the skin, linking it to deeper structures. Its insulation and energy stores contribute to temperature control and cushioning.