What are the primary functions of the integumentary system?

The integumentary system, which comprises the skin, hair, nails, and various glands, primarily serves to protect the body from external threats such as pathogens, chemicals, and physical injury. The skin acts as a barrier, preventing harmful substances from entering the body while also providing a waterproof layer that helps retain moisture.

In addition to its protective function, the integumentary system plays a critical role in regulating body temperature. It does this through mechanisms such as sweating and the dilation or constriction of blood vessels. When the body temperature rises, sweat glands produce moisture that evaporates from the skin's surface, helping to cool the body. Conversely, when the body is cold, blood vessels constrict to minimize heat loss, maintaining core body temperature.

The other options refer to functions not primarily associated with the integumentary system. Hormone production is primarily the role of the endocrine system, digestion is facilitated by the digestive system, and filtering blood is a key function of the renal system. Thus, the role of the integumentary system as a protector and temperature regulator is fundamental to maintaining overall homeostasis within the body.