Which of the following best describes the integumentary system's role?

The integumentary system primarily consists of the skin, hair, nails, and glands, playing a crucial role in protecting the body from external factors such as bacteria, chemicals, and physical injuries. This protective covering acts as a barrier, preventing harmful substances from entering the body while simultaneously allowing for the release of waste through perspiration.

Temperature regulation is another vital function of the integumentary system. The skin helps maintain a stable internal temperature through processes like sweating, which cools the body when it overheats, and by adjusting the flow of blood to the extremities, which can either preserve heat or dissipate it in response to changes in environmental temperature.

The other options relate to functions of different systems in the body. The production of white blood cells is primarily associated with the immune system. The storage of energy and nutrients is mainly a function of the metabolic system, particularly within tissues and organs like the liver and adipose tissue. Lastly, the transport of oxygen in the bloodstream is the primary role of the circulatory system, facilitated by red blood cells. Therefore, the best description of the integumentary system’s role revolves around its functions in protection and temperature regulation.