What is NOT a function of the integumentary system?

The integumentary system, which includes the skin, hair, nails, and glands, serves several vital functions that contribute to the body's overall health and homeostasis. Among these functions are water retention, thermoregulation, and vitamin D synthesis, all of which play essential roles in maintaining bodily function.

Water retention is crucial as the skin acts as a barrier that prevents excessive loss of water, helping to maintain hydration levels within the body. Thermoregulation is another vital function, as the skin helps to regulate body temperature through processes such as sweating and the dilation or constriction of blood vessels. Furthermore, the skin plays a key role in the synthesis of vitamin D when exposed to sunlight, which is important for calcium absorption and bone health.

In contrast, blood formation is primarily the responsibility of the bone marrow, where red and white blood cells are produced. The integumentary system does not play a direct role in this process. Therefore, the correct identification of blood formation as not being a function of the integumentary system highlights the specific roles assigned to different systems in the body.