Which system includes the skin, hair, nails, and glands?

The integumentary system is comprised of the skin, hair, nails, and glands, serving as a protective barrier for the body. Its primary functions include protection against environmental hazards, regulation of body temperature, and sensory perception. The skin, the largest organ of the body, plays a critical role in these processes by forming a physical barrier, participating in immune responses, and producing essential substances like Vitamin D.

Hair and nails contribute to protection as well, with hair helping to regulate temperature and offering some protection from UV radiation, while nails protect the sensitive tips of fingers and toes. The glands within the integumentary system, such as sweat and sebaceous glands, help maintain homeostasis by regulating moisture and oil levels, further enhancing skin integrity and function.

The other systems listed do not encompass these specific components: the muscular system relates to muscle tissues and movement, the endocrine system is involved with hormone production and regulation throughout the body, and the nervous system is responsible for transmitting signals and processing information. These distinctions highlight the unique role of the integumentary system in overall body health and protection.