What does the integumentary system primarily consist of?

The integumentary system primarily consists of skin and associated structures, which include hair, nails, and glands (such as sweat and sebaceous glands). This system serves multiple critical functions, including protection against pathogens, regulation of body temperature, and sensory perception. The skin acts as a barrier to external elements, while the associated structures play roles in various physiological processes.

The other options do not accurately reflect the components of the integumentary system. Muscles and bones are part of the musculoskeletal system, and nerves and blood vessels are components of the nervous and circulatory systems, respectively. While organs and glands can be part of many body systems, they do not specifically encompass the unique characteristics and components of the integumentary system as accurately as skin and its associated structures.