What system in the human body is responsible for protecting against germs?

The immune system is the primary defense mechanism in the human body against pathogens such as bacteria, viruses, fungi, and parasites. It consists of a network of cells, tissues, and organs that work together to identify and neutralize foreign invaders. Key components of the immune system include white blood cells, antibodies, and various signaling molecules that coordinate responses to infections and diseases.

The immune system operates through various processes, including the recognition of pathogens by immune cells, the production of antibodies to target specific invaders, and the activation of inflammatory responses that help contain and eliminate infections. This system is vital for maintaining health and preventing illnesses.

In contrast, the nervous system is primarily responsible for coordinating movements and processing sensory information, while the circulatory system focuses on the transportation of blood, nutrients, gases, and waste products throughout the body. The respiratory system's main role is to facilitate breathing and gas exchange, bringing oxygen into the body and expelling carbon dioxide. These systems, while essential for overall bodily function, do not specifically target germs or provide immunity in the way that the immune system does.