What is the primary function of the integumentary system?

The primary function of the integumentary system is to protect the body and regulate temperature. This system includes the skin, hair, nails, and associated glands, all of which serve crucial protective roles. The skin acts as a barrier against pathogens, harmful substances, and physical injuries, helping to maintain overall health and prevent infections.

Additionally, the integumentary system plays a vital role in thermoregulation. It helps to maintain the body's internal temperature through processes like sweating and the dilation or constriction of blood vessels. When the body becomes overheated, sweat glands produce sweat that evaporates, cooling the skin and the blood. Conversely, when it is cold, blood vessels constrict to reduce blood flow to the skin, conserving body heat.

In contrast, the other options describe functions associated with different systems of the body. The urinary system is responsible for filtering blood and producing urine; the digestive system facilitates digestion and nutrient absorption; and the circulatory system transports hormones and nutrients. Each of these systems has distinct and critical functions that support overall bodily health but do not pertain to the primary responsibilities of the integumentary system.