What components make up the integumentary system?

The integumentary system is primarily composed of skin, hair, and nails. Skin serves as the largest organ of the body, acting as a protective barrier against external environmental factors, regulating temperature, and facilitating sensory perception. Hair is also significant as it provides insulation, protection, and helps in the sensory function. Nails protect the distal phalanx and enhance the ability to grasp and manipulate objects.

While the skin is a component in other options, they include elements that do not belong to the integumentary system, such as muscles or bones, which are part of the muscular and skeletal systems, respectively. The inclusion of blood vessels and nerves focuses more on the supportive functions of the integument rather than the primary components that define the system. Thus, the correct answer highlights the main elements that are fundamentally identified as part of the integumentary system.