beskyttelsesvæv

Beskyttelsesvæv, or protective tissue, is a category of connective tissue in animals that provides structural support and protection to various organs and body systems. The most common types include skin, which serves as an external barrier against pathogens and mechanical injury; cartilage, which cushions joints and maintains shape in structures such as the ears and nose; and bone, which offers rigidity and a protective framework for internal organs.

Skin, the largest organ, consists of a epidermal layer rich in keratinocytes and a dermal layer containing collagen fibers, elastic fibers, and a network of blood vessels and nerves. It acts as a first line of defense, preventing entry of microbes and regulating water loss. Cartilage, unlike bone, is avascular and relies on diffusion for nutrient delivery; it is categorized into hyaline, fibrocartilage, and elastic cartilage, each adapted to specific mechanical functions. Bone is a dynamic tissue composed of cortical and cancellous structures, containing osteoblasts, osteoclasts, and osteocytes that remodel the mineral matrix.

Protective tissues are integral to both vertebrate and invertebrate physiology. In invertebrates, exoskeletons made of chitin provide mechanical support and protection, and can be considered a type of protective tissue. In mammals, the endosteum lining bone cavities and the periosteum covering bone surfaces further enhance bone resilience.

Research into protective tissues focuses on regeneration, injury repair, and disease—such as osteoporosis that weakens bone, or skin conditions that compromise barrier function. Advances in stem cell biology and tissue engineering aim to restore or replace damaged protective tissues, offering therapeutic strategies for conditions ranging from traumatic injuries to chronic degenerative diseases.