How does the integumentary system help regulate a decrease in body temperature?

The integumentary system plays a crucial role in temperature regulation, particularly through the actions of blood vessels in the skin. When the body temperature rises, dermal blood vessels dilate, allowing more blood to reach the surface, where heat can dissipate into the environment. Conversely, when the body temperature decreases, the body aims to conserve heat by stimulating the contraction of dermal blood vessel muscles. This vasoconstriction reduces blood flow to the skin, minimizing heat loss and preserving core body temperature.

While increasing sweat gland activity (the first choice) helps in cooling the body when overheated, it does not relate to decreasing body temperature. Shivering (the third choice) is a response to cold that generates warmth through muscle activity, but it is not a direct mechanism of the integumentary system. Increasing blood flow to the surface of the skin (the fourth choice) is also incorrect in the context of conserving heat, as this would lead to further heat loss rather than retaining warmth. Therefore, stimulating contraction of dermal blood vessels is an effective strategy the integumentary system employs to manage body temperature in cold conditions.