What comprises the structure of nerve receptors?

Nerve receptors, specifically those that detect sensations such as touch, temperature, and pain, are primarily composed of nerve endings that are often encapsulated or surrounded by connective tissue. This arrangement allows the receptors to be more sensitive to stimuli and helps protect the delicate nerve fibers. The connective tissue can provide structural support and enhances the function of the receptors by facilitating their interaction with various stimuli in the environment.

In comparison, muscle fibers, blood vessels, and hair follicles do not primarily form the structure of nerve receptors. Muscle fibers are involved in movement and are not associated with sensory perception in the same way. Blood vessels are part of the vascular system, providing nutrients and oxygen but not involved directly in sensation. Hair follicles, while they do have associated nerve endings that help detect movement or vibration, are not themselves the main structural component of nerve receptors. Thus, the correct choice illustrates the specific structure most relevant to the functioning of nerve receptors in the integumentary system.