What is the function of the immune system?

The immune system plays a crucial role in protecting the body from infections and diseases. Its primary function is to identify and eliminate pathogens such as bacteria, viruses, fungi, and parasites that can cause harm. This defense mechanism involves various components, including white blood cells, antibodies, and specialized proteins, all working together to recognize and respond to foreign invaders. When a pathogen is detected, the immune system activates and coordinates a response to neutralize or destroy it, thereby helping to maintain overall health and prevent illness. This protective function is essential for survival, as it enables the body to resist infections and recover from harmful agents that infiltrate the system.

The other options represent functions of different systems in the body. The breakdown of food into nutrients pertains to the digestive system, pumping blood is the responsibility of the circulatory system, and the transport of oxygen and nutrients falls under the functions of the respiratory and circulatory systems. These functions, while vital to bodily health, do not relate to the specific role of the immune system.