What is the primary function of the immune system?

The primary function of the immune system is to protect the body against infections and diseases. This complex network of cells, tissues, and organs works collaboratively to identify and neutralize harmful pathogens such as bacteria, viruses, fungi, and parasites. When the immune system detects these invaders, it triggers a response that can involve various cells and mechanisms, including the production of antibodies and the activation of immune cells to attack and destroy the pathogens.

Understanding this function emphasizes the critical role the immune system plays in maintaining overall health, preventing illnesses, and ensuring the body's defenses remain robust against various threats. This protection is vital, as a compromised immune system can lead to increased susceptibility to infections and diseases, highlighting the importance of a well-functioning immune system as the body's primary defense mechanism. The other options, while they may refer to important bodily functions, do not pertain to the immune system's role in defending against disease.