Integumentary System, Wound Healing, and Thermoregulation

Vocabulary flashcards covering skin layers, dermal structure, stages of wound healing, vascular responses, and thermoregulation mechanisms.

Epidermal layer

The outer layer of skin that prevents water loss and the entry of organisms.

Sensory receptors

Structures in the skin that provide input about the environment and its conditions.

Dermal blood supply

Blood supply located in the dermis that maintains body temperature.

Dermal papillae

Structures that support hair and skin.

Basale

Epidermal layer undergoing rapid mitosis, containing melanocytes and Merkel cells for light touch.

Spinosum

Epidermal layer containing dendritic cells and spiny cells bound by desmosomes to resist pulling.

Granulosome

Epidermal layer responsible for waterproofing and cell death, where cells flatten and gain keratin or glycolipids.

Lucidum

Epidermal layer found in thick skin only, composed of flat, thin keratinocytes.

Corneum

Epidermal layer made of $20-30$ layers of dead flat cells.

Papillary layer

Upper $20\%$ layer of dermis made of loose areolar tissue and dermal papillae creating fingerprints; feeds the epidermis and contains pain receptors.

Reticular layer

Lower $80\%$ layer of dermis providing strength and elasticity; consists of dense irregular tissue with fibers, and houses glands and follicles.

Hemostasis

The immediate clotting stage of wound healing involving vasoconstriction to restrict blood flow, plug the wound, and create a blood clot or scab.

Inflammatory phase

The clean-up stage of wound healing (day $1-6$) where vasodilation widens vessels, flooding the area with fluid and immune cells while white blood cells swallow pathogens and debris.

Proliferation phase

The rebuilding stage of wound healing (days $4-24$) where fibroblasts form temporary collagen scaffolding, new small vessels supply nutrients, granulation tissue forms, and epithelial cells reseal the surface.

Maturation phase

The strengthening stage of wound healing where old collagen scaffolding is replaced with stronger collagen.

Angiogenesis

The process where new blood cells are made from old ones.

Vasodilation

Widening of blood vessels that relaxes blood vessel smooth muscle and lowers pressure; triggered by heat, low oxygen, or exercise.

Vasoconstriction

Narrowing of blood vessels that makes internal space smaller; triggered by cold, stress, or epinephrine.

Thermoregulation

The process of keeping internal temperature within a safe range despite outside temperature.

Sweating

Thermoregulatory response to heat where sweat glands release moisture that evaporates to keep the body cool.

Lethargy (in thermoregulation)

Thermoregulatory response to heat where the brain signals muscles to relax.

Shivering

Thermoregulatory response to cold where involuntary muscles contract to create heat.

Thermogenesis

process of heat production in organisms