The document summarizes the integumentary system of vertebrates. It describes the three main layers - epidermis, dermis, and basement membrane complex. The epidermis contains stratified layers that produce keratin, while the dermis contains connective tissue, blood vessels, glands, and nerves. The system serves various functions like protection, thermoregulation, and sensory reception. Skin appendages like scales, feathers, and hairs vary across vertebrate classes.