Nails are a part of which body system?

Nails are a component of the integumentary system, which encompasses the skin, hair, nails, and various glands. This system serves critical functions including protection of underlying tissues, regulation of body temperature, and sensation. Nails specifically protect the distal ends of fingers and toes, enhance the ability to pick up small objects, and serve as a protective barrier for the sensitive tips of the digits.

In contrast, the circulatory system is responsible for transporting blood and nutrients throughout the body; the muscular system pertains to the muscles and movement; and the nervous system includes the brain, spinal cord, and nerves, which control bodily functions and responses. Thus, identifying the integumentary system as the correct answer highlights its role in encompassing nails and their functions.