Which of the following is not a part of the pilosebaceous unit?

The pilosebaceous unit is a structure within the skin that consists of several components, primarily the hair follicle, sebaceous glands, and arrector pili muscles. The sebaceous gland is responsible for producing oil that helps to maintain the health and integrity of the hair and skin. The hair follicle serves as the growth site for hair, while the arrector pili muscle is attached to the follicle and causes hair to stand upright when it contracts, contributing to the body's response to cold or emotional stimuli.

The sudoriferous gland, on the other hand, is responsible for sweat production and is not involved in the hair growth or oil production associated with the pilosebaceous unit. Thus, it does not belong to this specific structure. Understanding the functions and components of the pilosebaceous unit is essential for recognizing how skin health is maintained and how various skin conditions may arise when one component is impaired.