The document discusses the integumentary system, which includes the skin, hair, and nails. The skin acts as a protective barrier and helps regulate body temperature through sweating and blood vessel dilation. It also enables our sense of touch. The skin has two layers - the outer epidermis made of dead skin cells, and the inner dermis of connective tissue. The dermis contains hair follicles, sweat glands, and sebaceous glands. The document provides tips to prevent skin cancer such as seeking shade, wearing sunscreen, and checking your skin regularly.