Illustrate the structure and function of hair, nails, sweat glands, and oil glands. What is the function of the hair papilla? A.) The hair papilla makes new keratinocytes that make up hair. B.) The hair papilla connects the hair root to the dermis. C.) The hair papilla is involved in thermoregulation. D.) The hair papilla supplies blood vessels and nerves to the hair follicle.
The correct answer and explanation is:
The correct answer is D) The hair papilla supplies blood vessels and nerves to the hair follicle.
Explanation:
The hair papilla is a small, bulbous structure located at the base of the hair follicle. It contains capillaries (small blood vessels) and nerve endings that play crucial roles in hair growth and health. The blood vessels within the hair papilla provide the necessary nutrients and oxygen to the growing hair, allowing it to thrive. The nerve endings in the papilla are involved in sensory functions, allowing the body to respond to changes in the environment, such as the sensation of touch when hair is moved or disturbed.
The hair follicle itself is a tunnel-like structure in the skin that houses the hair shaft. The hair growth occurs in the hair matrix, a region near the hair papilla, where cells divide rapidly and produce keratinocytes. These cells differentiate and form the hair shaft as they move upward through the follicle. The papilla ensures that the hair follicle receives proper nourishment to maintain this growth.
In terms of other skin structures:
- Hair functions in protection, sensory input, and thermoregulation. It helps to retain heat and provides a barrier against foreign particles.
- Nails are composed of hard keratin and help in manipulating objects, protecting the tips of fingers and toes, and enhancing the sense of touch.
- Sweat glands help regulate body temperature by secreting sweat, which cools the body when it evaporates.
- Oil glands (sebaceous glands) secrete sebum, an oily substance that lubricates the skin and hair, preventing them from drying out.
Thus, the hair papilla plays a vital role in nourishing the hair follicle, which is essential for healthy hair growth and overall hair function.