Which of the following are considered accessory organs of the skin?

Accessory organs of the skin include structures that support, protect, and enhance the functionality of the skin itself. Hair, nails, and exocrine glands are defined as accessory organs because they are closely associated with the skin and contribute to its overall role in the body.

Hair serves several functions, including protection, thermoregulation, and sensory perception. Nails provide protection for the tips of fingers and toes and assist in fine motor tasks. Exocrine glands, such as sweat glands and sebaceous glands, play critical roles in thermoregulation, hydration, and protection against microbial invasion by producing sweat and sebum, respectively.

These features emphasize how hair, nails, and glands are integral to maintaining the health and functionality of the skin, working together to enhance the skin's protective barrier while also participating in various physiological processes. The other options listed—muscles, nerves, and blood vessels—are indeed important components associated with the skin but are not classified as accessory organs. Rather, they are part of the skin's structural framework, contributing to its function and health from a different perspective.