Final answer:
The accessory structure not found within the dermis was a trick choice; in fact, all listed structures, including the arrector pili muscle, lamellated corpuscle, sebaceous gland, and tactile corpuscle, are found within the dermis.
Step-by-step explanation:
The accessory structure not found within the dermis is E) All of the listed structures are found within the dermis.
Explanation: The dermis is the thick layer of skin that lies beneath the epidermis and contains connective tissue, blood vessels, nerves, and muscles. Accessory structures such as hair follicles from which the hair grows, and glands like sweat glands and sebaceous glands are embedded within the dermis. Arrector pili muscles are small muscles attached to hair follicles, which cause the hair to stand on end when they contract. Similarly, the tactile corpuscles, or Meissner's corpuscles, and the lamellated corpuscles, or Pacinian corpuscles, which are types of mechanoreceptors involved in the sense of touch, are also located in the dermis. Thus, all the mentioned structures (A, B, C, and D) are indeed found within the dermal layer.
The accessory structure that is NOT found within the dermis is the tactile corpuscle. Tactile corpuscles, also known as Meissner's corpuscles, are located in the upper dermis but project into the epidermis. They are primarily found in glabrous skin on the fingertips and eyelids.